Etymology: In sense 1, < Old French tramail (c1220 in Godefroy Compl.), modern French trémail a fishing- or fowling-net, with three layers of meshes, = Italian tramaglio, Spanish trasmallo, Portuguese trasmalho < late popular Latin tramaculum for tri-, tremaculum (in Salic Law, Hessels, Cod. 1, xxvii. 20, tremaclem, v.rr. tremalem, tremagilo, tramaculam, trimaclem, tremagolum, tremachlum, etc.) a kind of fishing-net, generally explained as < Latin tri- three + macula mesh. In the Romanic languages the prefix appears to have been taken as = tra-, Latin trans.The history of the other senses here included is difficult. French dictionaries have trémail, tramail, only in senses 1a, 1b And indeed the sense-connection of branches II, III, IV with I, and with each other, is obscure; some of them may perhaps be different words. But the identification of I and II is not confined to English. Du Cange quotes a medieval Latin statute of Piacenza, in which tramaiolum (? read tramacolum) is applied to a stick a cubit and a half long, ordered to be fixed to the necks of dogs to prevent them from running into vineyards or other places where they might do mischief; and he identifies this word with Italian tramaglio and French tramail, and refers to this word as known to be applied not only to a net, but to any kind of shackle or snare (pedica). Baretti's Italian dictionary has tramaglio only as ‘a trammel or dragnet’, but Florio 1611 has it ‘a tramell or ensnaring’.

Etymology: Compare Old French tremuie , tremue , tremee (all 14th cent. in Godefroy), trameul , tremouille , tremuë (Cotgrave), modern French trémie = Provençal tremueia , Catalan tramuja , Italian tramoggia , Sicilian trimoja < Latin trimodia , a three-peck measure: see Diez, Scheler. Some medieval Latin and Romanic forms are affected by Latin tremĕre to tremble. In English apparently confounded with trammel n.¹

Etymology: < trammel n.¹Previous versions of the OED give the stress as: ˈtrammel.