| 释义 |
drop-out
Also dropout.
[drop v. 29.]
1. Rugby Football. A drop-kick made from within the defending side's twenty-five-yard line in order to restart play after the ball has gone dead.
1882[see drop-kick]. 1896Laws of Football 3 Drop-out is a drop-kick from within 25 yards of the kicker's goal line. 1896Durham Univ. Jrnl. 21 Mar. 69 The drop-out was well followed up. 1905Westm. Gaz. 12 Dec. 9/2 From the drop-out Cambridge began an attack. 1960E. S. & W. J. Higham High Speed Rugby xiii. 157 The kick⁓off, drop-out, penalty and free kick.
2. A person who ‘drops out’ (see drop v. 29 b), esp. from a course of study or from society; also, the act of withdrawing. Also attrib. colloq. (orig. U.S.).
1930Sat. Even. Post 1 Mar. 110/2 The drop-outs are usually those with inferior mental capacity. 1960Times 21 Nov. (Canada Suppl.) p. xviii/4 The bored students—mostly boys—and the ‘drop outs’. 1962Guardian 19 Jan. 8/5 The brilliant woman..becomes an embarrassing statistic in the academic ‘drop-out’ rate... Dr. Bunting was a ‘drop-out’ for six years when her children were young. 1966Listener 29 Sept. 454/3 The older teachers are resigned to the low standards and the high rate of drop-out. 1967New Statesman 15 Dec. 838/2 An international gathering of misfits and drop-outs, smoking pot and meditating in the Buddhist temples. 1970New Society 5 Feb. 231/3 He seems to imagine that, with the exception of the drop-outs, the working class has been entirely absorbed in ‘co-operative economic production and consenting political citizenship’. 1971Brit. Med. Bull. XXVII. 5/1 Experience suggests a high drop-out rate for those being treated.
3. Photogr. The elimination of highlight dots from part of a half-tone negative or plate; also, a half-tone having such an area eliminated, or the area itself. Also attrib.
1948Flader & Mertle Mod. Photoengraving p. xxi/2 Dropout, a highlight halftone negative or printing plate; ‘dropping-out’ is the elimination of highlight dot formations. 1967Karch & Buber Offset Processes v. 179 The drop-out halftone..is made where it is desirable to eliminate the highlight background of an illustration. 1968Gloss. Terms Offset Lithogr. Printing (B.S.I.) 11 Drop-out, the areas of a picture which are clear of printing image. Ibid. 17 Drop-out mask, a photographic mask of sufficient density and contrast to separate non-printing areas from the first printing tones.
4. In tape-recording, a momentary decrease in the amplitude of the recorded signal due to a flaw in the tape; also, such a flaw.
1955Jrnl. Audio Engin. Soc. III. 31 Tape squeal, sticking, and level variations have been caused by deposits on the head due to the shearing of imperfections in the oxide. Because of the effect of level variation in the computer field, the latter phenomenon has generally been referred to as ‘dropout’. 1958Engineering 7 Mar. 310/2 When the signal amplitude falls below this limit, faulty reproduction of the signal occurs. This is called ‘drop-out’. 1962A. Nisbett Technique Sound Studio iv. 85 Where there is a slight flaw, such as a drop-out, making a simple joint (and removing the flawed scrap of tape) will save time. 1967D. F. Eldridge in C. B. Pear Magn. Recording iii. 101 Once the first permanent dropout is formed, additional dropouts in increasing numbers will follow rapidly.
Senses 2–4 in Dict. become 3–5. Add: 2. Cycling. Either of two U-shaped slots at the end of a fork or stay, made to receive the axle and enabling the wheel to be changed rapidly or its position adjusted. Usu. in pl.
1923Cycling Man. (ed. 5) x. 55 (caption) An example of a straight drop-out (The Allun). 1973R. J. Way Bicycle 37 (caption) Campagnolo quick-release hub, and rear drop-outs. 1986Bicycle July 27/2 In an ideal world, everyone would have vertical drop-outs; provided the rear end is true, the wheel should slip in and out with no need for adjustment in a matter of seconds. |