Etymology: < (i) Anglo-Norman plom, plombe, plomme, plum, plumb, etc. and Middle French plom, plomb, plumbe (French plomb ) (end of the 11th cent. in Old French in sense ‘lead’; 1260 in Old French in sense 1a; second half of the 13th cent. or earlier in Anglo-Norman in sense 2b; c1272 or earlier in Anglo-Norman in sense ‘loaded javelin’, in a translation of Vegetius, but apparently unparalleled in continental French in sense 2a until considerably later (c1600); sense 1b is apparently not attested in Middle French before 1530 (in the phrase plomb de sonde sounding lead), but compare Old French plomme (1309 in this sense in an apparently isolated attestation)), and its etymon (ii) classical Latin plumbum lead, ball of lead used as a missile, in post-classical Latin also scourge weighted with pieces of lead (4th cent.), lead weight in a clock (1371 in a British source); a loanword, apparently from the same source as ancient Greek μόλυβδος lead, probably from an Iberian language (lead came to the Greeks and Romans originally from Spain). In sense 3 < plumb v. Compare Old Occitan plom , (rare) plum , Catalan plom (1249), Spanish plomo (1243), Portuguese chumbo (1266 as chunbo ), Italian piombo (end of the 13th cent.), all earliest in general sense ‘lead’, but from an early date also in a range of spec. uses paralleling those in English. With plumb right adj. at Compounds compare plumb adj., plumb adv.Recorded earliest in the compound blank plumb at blank adj. 1:a1350 Recipe Painting in Archæol. Jrnl. (1844) 1 65 Vorte maken blankplum. Tac a vessel of eorthe other of treo. It is unclear whether the following quot. (compare sense 2b) is to be interpreted as showing the Middle English or the Anglo-Norman word:1349 in J. Raine Fabric Rolls York Minster (1859) 19 Item, ij plumes pro orilogio ponderantes xxij petras.

Etymology: < plumb v. Compare plunge n. 4a.

Etymology: Apparently partly < plumb n.¹, partly < plumb adv., and partly < plumb adj. With sense 3 compare Middle French, French plomber to check (a wall) against a plumb line (1598; compare Middle French plommer to put (an object) in a vertical position using a plumb line (end of the 14th cent.)). In branch II. probably after Middle French plommer, plomber, French plomber (12th cent. in Old French in past participle (plural) ploumes in sense 5, 1372 or earlier in Middle French in sense 6; earlier in sense ‘to cover with lead’ (end of the 11th cent. in Old French as plomer , in a gloss in Rashi)). In branch III. after plumber n., plumbing n. Compare classical Latin plumbāre to weight with lead, to fasten with lead, in post-classical Latin also to roof with lead (frequently 1199–1433 in British sources), Old Occitan plombar (Occitan plombar ) (intransitive) to fall (second half of the 12th cent. or earlier), (transitive) to load (a die) (a1126), to throw (a leaded line, in sea fishing), to cover (an object) with lead (both early 13th cent. or earlier), Catalan plomar to affix a leaden seal to (an object) (1514 or earlier), Spanish plomar to affix a leaden seal to (a document, merchandise, etc.) (first half of the 13th cent. or earlier, frequently in past participle plomado ), Italian piombare , †plombare to be vertical (a1321), to affix a leaden seal to (a document, merchandise, etc.) (1398 in past participle †plombada ), to fall down from a height (1475–8). Compare earlier plunge v.

Etymology: < plumb n.¹ With sense A. 1a compare Middle French a plon vertically, straight down (c1180 in Old French; Middle French, French à plomb (1552)), Italian a piombo vertically, straight down (a1363). The French phrase is apparently not paralleled in sense A. 1b until later (end of the 17th cent.); use of the noun as adverb or adjective is apparently not attested in French. With sense A. 2b compare plump adv. 3. With sense A. 2c compare slightly later plump adv. 4.