Etymology: < Anglo-Norman and Middle French pestel (c1180 in Old French; also in Anglo-Norman as pestle and in Old French as pestal ; now regional) club-shaped instrument in a mortar (c1180), in Anglo-Norman also the foreleg of an animal used as food (c1330 or earlier) < an unattested post-classical variant *pistellum (with suffix substitution: see -ellum suffix) of classical Latin pistillum , pistillus (in post-classical Latin also pestillum , in undated glossaries, and pestellum , from the late 13th cent.) pounder, pestle < the stem of pīlum pile n.¹ + -illus , -illum (see -illa suffix). In forms with -i- in the first syllable perhaps after the classical Latin word. Compare Old Occitan pestel , Italian pestello (1348–53 in obscene sense ‘penis’, second half of the 14th cent. in sense 1a; also as pistillo (a1498 or earlier, now literary)).It is unclear whether the following early examples are to be interpreted as showing the Middle English or the Anglo-Norman word:1345–9 Wardrobe Acct. Edward III in Archaeologia (1846) 31 81 j pestell de ferro.1363 in H. T. Riley Memorials London (1868) 312 [The best] pestelle [of pork, 3 d.] Apparently attested earlier as a surname: Randolph Pestel (1280, in a late copy (17th cent.)), John Pestell (1289), William Pestel (1296), although it is unclear whether these examples are to be interpreted as reflecting the Middle English or the Anglo-Norman word. Compare post-classical Latin pestelellum in a British source:1272 in J. E. T. Rogers Hist. Agric. & Prices (1866) (modernized text) II. 566 Mortar cum pestelello. In quots. at sense 2 translating classical Latin trībulum threshing-sledge (see tribulation n.). With sense 4a compare post-classical Latin pestellum porci leg of pork (1307, 15th cent. in British sources).

Etymology: Either < pestle n., or < Anglo-Norman and Middle French pesteler to pound, crush, mash (12th cent. in Old French; French (now regional) pesteler , peteler ; < pestel pestle n.).