lbn.
†A pound sterling (obsolete); (now) a pound in weight. lbf n. the pound as a unit of force. lbm n. the pound as a unit of mass.
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the world > relative properties > measurement > measurement by weighing > [noun] > unit or denomination of weight > pound
poundeOE
poundeOE
wey?c1225
lb1390
li.c1450
pound-weight1466
litre1603
the world > matter > physics > mechanics > force > [noun] > units of force
pound-weight1824
pound-force1865
gram weight1871
dyne1873
kilodyne1873
poundal1875
Gramme1884
Newton1904
kilogram force1905
gram force1909
kip1915
N1951
lbf1961
ounce-force1961
ton-force1961
1390–1 Earl Derby's Exped. (Camden) 11 Pro ij lb. gyngere, ijs. xd.
?1566–7 G. Buchanan Opinion Reformation Univ. St. Andros in Vernacular Writings (1892) 7 In silver, five hundret xlvij lbs. xs. xd.
1961 B.S.I. News Oct. 26/1 The B.S.I. committee which deals with units and symbols has accepted a form of notation in which a distinction is made between the two concepts ‘mass’ and ‘force’. In this notation the pound has the abbreviation ‘lb’; the unit called a pound-force has the abbreviation ‘lbf’ and is that force which, when acting on a body of mass one pound, gives it an acceleration equal to that of standard gravity.
1962 S. L. Bragg Rocket Engines ix. 148 A jet velocity of 105 ft/s could be obtained, giving a thrust of 3 lbf for a flow of 0·0009 lbm/s.
1966 G. W. C. Kaye & T. H. Laby Tables Physical & Chem. Constants (ed. 13) 6 It is convenient to distinguish the basic units of force in gravitational systems from the basic units of mass in other systems by using the symbols kgf for the kilogramme-force and lbf for the pound-force.
1967 Technol. Week 23 Jan. 104/1 (advt.) Pictured from the top: 300 lbf monopropellant hydrazine rocket for orbit control.
1971 I. H. Shames Introd. Statics i. 12 (table) 1 slug ≡ 32·2 lbm.
This entry has not yet been fully updated (first published 1902; most recently modified version published online June 2018).
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