Of unknown origin. Perhaps from Proto-Indo-European *peyg- (“inactive, reluctant”), and cognate with Latin piger (“dull, lazy”). Liukkonen mentions a Finnish pika (“quick, fast”) possibly being borrowed from the same origin as the Lithuanian; however, the existence of such a word in Finnish is in question (pika in Finnish seems to exist only as a borrowing from English, referring to the lagomorph). The family of words including pi̇̀ktas (“angry, vicious”), pei̇̃kti (“to blame, reprehend”), pai̇̃kas (“silly, foolish”), pỹkti (“to be angry”), and pikùlas (“devil”) appears to be connected, though this family seems to trace to a different Proto-Indo-European root; perhaps the two roots were confused within Baltic.