† subtrayv.

Etymology: Probably partly (i) < classical Latin subtrahe, imperative singular of subtrahere subtract v.; partly (ii) < classical Latin subtrah-, stem of subtrahere subtract v.; and partly (iii) < Anglo-Norman subtrere, subtreer, subtreere and Middle French subtraire to subtract (second half of the 13th cent. in Old French in mathematical use), to withdraw (1315 or earlier in Anglo-Norman, used reflexively), to remove (something) (a1419 or earlier in Anglo-Norman), to withdraw (something beneficiary) from a person (a1436 or earlier in Anglo-Norman), an alteration (after classical Latin subtrahere ) of Anglo-Norman sustrere , sustraire , sostrere , souztraire , souztrere , suztraire , suztreire , Old French sostraire , soztraire , Middle French soubtraire , substraire , soustraire to subtract, to remove, to take away, to withdraw, etc. (first half of the 12th cent. in Old French; French soustraire ) < classical Latin subtrahere , with prefix substitution in French (see sous- prefix). Compare Old Occitan sostraire (12th cent.), Spanish substraer (late 14th cent.), sustraer (second half of the 15th cent.), Portuguese subtrair (1683 as †subtrahir ), Italian sottrarre (a1321). Compare later substra v., substract v., subtract v.