step-downadj.n.

Etymology: < verbal phrase to step down: see to step down at step v. Phrasal verbs 1.Previous versions of the OED give the stress as: ˈstep-down.

A. adj.

1. Causing or relating to a reduction in voltage or some other quantity (see to step down 3 at step v. Phrasal verbs 1).

ΘΚΠ

the world > matter > physics > electromagnetic radiation > electricity > voltage > [adjective] > relating to increase or decrease

step-down1893

step-up1893

the world > matter > physics > electromagnetic radiation > electricity > electrical engineering > transformer > [adjective] > causing increase or decrease

step-down1893

step-up1893

1893 T. O'C. Sloane Standard Electr. Dict. 494 Step-down adj...applied to a converter or transformer in the alternating current distribution, indicating that it lowers potential difference and increases current from the secondary.

1929 Exper. Wireless June 307/2 This reduces the step down ratio required in the potentiometer.

1947 R. Lee Electronic Transformers & Circuits vi. 172 Driver transformers are usually step-down because the grid potentials are relatively low.

1959 Motor Man. (ed. 36) 95 It has a stepdown gear which reduces the speed of the propeller shaft in a ratio which is usually between 5 to 1 and 4 to 1.

1961 Wall St. Jrnl. 14 Nov. 10 (advt.) With Con Edison's step-down rates, the more electricity you use, the less it costs per kilowatt-hour.

1981 Daily Tel. 22 July 12/6 For really rough going there is a 1·96:1 step-down ratio for four-wheel-drive.

2. Requiring, causing, or relating to a step from a higher level to a lower (see to step down 1 at step v. Phrasal verbs 1). Chiefly U.S.

ΘΚΠ

the world > movement > motion in a certain direction > downward motion > [adjective] > from or in which one steps down

step-down1949

1949 Newsweek 28 Nov. 56 (caption) Hudson enters lower-priced field with smaller version of step-down car.

1954 Sun (Baltimore) 8 Mar. 20/1 Dr. Clifford M. Witcher..calls his device a ‘step-down detector’. When the user approaches a curb, a flight of steps or the edge of a sub~way platform, the detector buzzes a warning.

1966 A. R. Bellamy in Biochimica et Biophysica Acta 123 102 (title) RNA synthesis in exponentially growing tobacco cells subjected to a step-down nutritional shift.

1976 Billings (Montana) Gaz. 27 June 5- d/4 (advt.) Three bedrooms, step-down living room, and main floor family room with fireplace.

B. n.

1. A reduction or decrease.

ΘΚΠ

the world > relative properties > quantity > decrease or reduction in quantity, amount, or degree > [noun] > instance of

downfall1654

fall1792

drop1847

cut1881

degrowth1920

step-down1922

rollback1942

1922 R. Glazebrook Dict. Appl. Physics I. 565/1 The usual process [for the commercial liquefaction of gases] is a regenerative one, first successfully developed by Linde, in which the Joule-Thomson effect of irreversible expansion in passing a constrictive orifice..serves as the step-down in temperature, and a cumulative cooling is produced by causing the gas which has suffered this step-down to take up heat in a thermal interchanger from another portion of gas that is on its way to the orifice.

1962 A. Nisbett Technique Sound Studio ix. 165 The result is a sudden step-down in volume and quality just before the second signal appears on the tape.

2. The act of stepping down or withdrawing from a position.

ΘΚΠ

the mind > will > decision > irresolution or vacillation > reversal of or forsaking one's will or purpose > [noun]

reversec1487

retraction1536

relent1580

declension1597

relentance1629

resentment1646

intercision1647

relenting1694

back-down1862

backing-down1883

back-pedalling1950

step-down1973

1973 Guardian 7 June 2/4 In a cleverly disguised step~down from the position that these controversial logs would never be released, Mr Nixon's spokesman said today that..the documents would now be turned over.

This entry has not yet been fully updated (first published 1986; most recently modified version published online December 2021).

单词	step-down
释义	step-downadj.n. Etymology: < verbal phrase to step down: see to step down at step v. Phrasal verbs 1.Previous versions of the OED give the stress as: ˈstep-down. A. adj. 1. Causing or relating to a reduction in voltage or some other quantity (see to step down 3 at step v. Phrasal verbs 1). ΘΚΠ the world > matter > physics > electromagnetic radiation > electricity > voltage > [adjective] > relating to increase or decrease step-down1893 step-up1893 the world > matter > physics > electromagnetic radiation > electricity > electrical engineering > transformer > [adjective] > causing increase or decrease step-down1893 step-up1893 1893 T. O'C. Sloane Standard Electr. Dict. 494 Step-down adj...applied to a converter or transformer in the alternating current distribution, indicating that it lowers potential difference and increases current from the secondary. 1929 Exper. Wireless June 307/2 This reduces the step down ratio required in the potentiometer. 1947 R. Lee Electronic Transformers & Circuits vi. 172 Driver transformers are usually step-down because the grid potentials are relatively low. 1959 Motor Man. (ed. 36) 95 It has a stepdown gear which reduces the speed of the propeller shaft in a ratio which is usually between 5 to 1 and 4 to 1. 1961 Wall St. Jrnl. 14 Nov. 10 (advt.) With Con Edison's step-down rates, the more electricity you use, the less it costs per kilowatt-hour. 1981 Daily Tel. 22 July 12/6 For really rough going there is a 1·96:1 step-down ratio for four-wheel-drive. 2. Requiring, causing, or relating to a step from a higher level to a lower (see to step down 1 at step v. Phrasal verbs 1). Chiefly U.S. ΘΚΠ the world > movement > motion in a certain direction > downward motion > [adjective] > from or in which one steps down step-down1949 1949 Newsweek 28 Nov. 56 (caption) Hudson enters lower-priced field with smaller version of step-down car. 1954 Sun (Baltimore) 8 Mar. 20/1 Dr. Clifford M. Witcher..calls his device a ‘step-down detector’. When the user approaches a curb, a flight of steps or the edge of a sub~way platform, the detector buzzes a warning. 1966 A. R. Bellamy in Biochimica et Biophysica Acta 123 102 (title) RNA synthesis in exponentially growing tobacco cells subjected to a step-down nutritional shift. 1976 Billings (Montana) Gaz. 27 June 5- d/4 (advt.) Three bedrooms, step-down living room, and main floor family room with fireplace. B. n. 1. A reduction or decrease. ΘΚΠ the world > relative properties > quantity > decrease or reduction in quantity, amount, or degree > [noun] > instance of downfall1654 fall1792 drop1847 cut1881 degrowth1920 step-down1922 rollback1942 1922 R. Glazebrook Dict. Appl. Physics I. 565/1 The usual process [for the commercial liquefaction of gases] is a regenerative one, first successfully developed by Linde, in which the Joule-Thomson effect of irreversible expansion in passing a constrictive orifice..serves as the step-down in temperature, and a cumulative cooling is produced by causing the gas which has suffered this step-down to take up heat in a thermal interchanger from another portion of gas that is on its way to the orifice. 1962 A. Nisbett Technique Sound Studio ix. 165 The result is a sudden step-down in volume and quality just before the second signal appears on the tape. 2. The act of stepping down or withdrawing from a position. ΘΚΠ the mind > will > decision > irresolution or vacillation > reversal of or forsaking one's will or purpose > [noun] reversec1487 retraction1536 relent1580 declension1597 relentance1629 resentment1646 intercision1647 relenting1694 back-down1862 backing-down1883 back-pedalling1950 step-down1973 1973 Guardian 7 June 2/4 In a cleverly disguised step~down from the position that these controversial logs would never be released, Mr Nixon's spokesman said today that..the documents would now be turned over. This entry has not yet been fully updated (first published 1986; most recently modified version published online December 2021). > as lemmas step-down C2. Combinations with an adverb, as step-back, step-down, step-up = an act of stepping backwards, etc. ΚΠ 1603 J. Florio tr. M. de Montaigne Ess. iii. xiii. 658 I begin to perceive a dimnes and weaknes in reading... Loe—heere a steppe-backe, and that very sensible. 1833 Regulations Instr. Cavalry i. i. 18 The ‘Step Back’ is performed in the slow time and length of pace, from the halt. extracted from stepn.¹ < adj.n.1893 as lemmas
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step-downadj.n.

> as lemmas