late 14c., from Old French pustule (13c.) and directly from Latin pustula "blister, pimple," from PIE imitative root *pu- (1) "blow, swell," on notion of "inflated area" (source also of Sanskrit pupphusah "lung," Greek physa "breath, blast, wind, bubble," Lithuanian pučiu, pūsti "to blow, swell," Old Church Slavonic puchati "to blow"). Compare emphysema. Related: Pustulant; pustular.

early 15c., from Middle French putatif, from Late Latin putativus "supposed," from Latin putat-, past participle stem of putare "to judge, suppose, believe, suspect," originally "to clean, trim, prune" (from PIE root *pau- (2) "to cut, strike, stamp"). At first especially in putative marriage, one which, though legally invalid, was contracted in good faith by at least one party. Related: Putatively.

c. 1400, from Old French putrefaction (14c.), from Latin putrefactionem (nominative putrefactio), noun of action from past-participle stem of putrefacere "to make rotten," from putrere "to be rotten" (see putrid) + facere "to make, do" (from PIE root *dhe- "to set, put").