The story
Uncertain. First appears in the 1820s. Perhaps a diminutive of pun, a dialect variant of pound, the weight + -et. The suggestion that it is an eponym of Reginald Crundall Punnett (1875–1967), geneticist and grower of strawberries, is not chronologically possible. The suggestion it was an ancestor of his lacks evidence. Very likely to have originated from the french word bannette, wicker basket for bread proofing.
Etymology from Wiktionary, CC BY-SA 4.0.