c.1290, "papal indulgence," from O.Fr.
pardonner "to grant, forgive," from V.L.
*perdonare "to give wholeheartedly, to remit," from L.
per- "through, thoroughly" +
donare "give, present." Meaning "passing over an offense without punishment is from c.1300; strictly legal sense is from 1328, in Anglo-Fr. Weaker sense of "excuse for a minor fault" is attested from 1548. The verb is first recorded c.1430.
" 'I grant you pardon,' said Louis XV to Charolais, who, to divert himself, had just killed a man; 'but I also pardon whoever will kill you.' " [de Sade]
Pardon my French as exclamation of apology for obscene language is from 1895. A
pardoner (1362) was a man licensed to sell papal pardons or indulgences.