1810, "member of a gang of murderers and robbers in India who strangled their victims," from Marathi
thag, thak "cheat, swindler," Hindi
thag, perhaps from Skt.
sthaga-s "cunning, fraudulent," possibly from
sthagayati "(he) covers, conceals," from PIE base
*(s)teg- "cover" (see
stegosaurus). Transferred sense of "ruffian, cutthroat" first recorded 1839. The more correct Indian name is
phanseegur, and the activity was described in Eng. as far back as c.1665. Rigorously prosecuted by the British from 1831, they were driven from existence, but the process extended over the rest of the 19c.