- verb to understand, ‘catch on’. A formerly raffish term which, since the late 1960s, has become a fairly common colloquialism. This usage has been recorded since the 18th century and derives either from ‘tweak’ in the sense of snatch or grasp or from a Gaelic verb meaning to comprehend.
Origin & History of “twig”
English has two separate words twig. The older, ‘small branch’ (OE), which has relatives in German zweig and Dutch tijg, appears to have been formed from the Germanic base *twi- ‘two’, and so etymologically it presumably denotes a ‘forked branch’. The origins of twig ‘catch on, understand’ (18th c.) are uncertain. It may be the same word as the contemporary but now defunct twig ‘pull’. this was presumably related to tweak (17th c.) and twitch (12th c.), which go back to a prehistoric Germanic base *twik-.