puzzle

The verb form is attested first, though its ultimate origin is uncertain. It's apparently cognate with a family of Germanic words for puttering, tinkering, or working slowly and carefully — including Scots pousle, Dutch peuzelen, Danish pusle, and Swedish pyssla — and may trace back to an early form 'pusle,' similar to Old English puslian, meaning 'to pick out the best bits.'

One theory suggests the sense drifted from 'picking out the best bits' to 'thinking long and carefully while choosing what to pick,' and finally to simply 'thinking long and carefully in bewilderment' — though no in-between forms have actually been found to confirm this path. The noun came later, growing out of the verb.

It shares a root sense of fiddly, careful labor with words like Danish pusle and Swedish pyssla, both meaning to putter or tinker at small tasks — the same patient fussing that puzzling out an answer requires.