pecadillo

Peccadillo entered English from Spanish pecadillo, the diminutive of pecado, meaning 'sin.' Pecado derives from the Latin peccatum, the past participle of peccare, meaning 'to sin' or 'to err.' The diminutive suffix -illo (feminine -illa) in Spanish reduces a noun to something smaller, lesser, or more endearing — making pecadillo literally 'a little sin,' a minor offense not worth serious condemnation. The word arrived in English in the late sixteenth century, first recorded around 1591 in Thomas Nash's Preface to Sidney's Astrophil and Stella. Its adoption was rapid, suggesting English speakers immediately recognized the need for a word that Latin had not supplied so neatly.

Latin peccare and its derivatives cover an interesting semantic range. The noun peccatum (sin) is the basis of peccadillo; the verb peccare means both 'to sin' and more broadly 'to err,' 'to make a mistake,' 'to commit a fault.' In medieval Christian moral theology, sins were categorized by gravity: mortal sins (which imperiled the soul) and venial sins (minor transgressions). Peccadillo occupies the far venial end of this spectrum — the theological category made linguistic, a word for the sins so small they barely count. The Scholastic philosophers who used Latin peccare would have understood immediately what a pecadillo was.

In early modern English, peccadillo was sometimes spelled 'peccadill,' and in the late sixteenth and early seventeenth centuries this form gave rise to 'picadil' or 'piccadill' — the name of a type of ornamental collar or lace edge fashionable in Elizabethan and Jacobean clothing. The connection between the minor sin and the collar is uncertain, with some etymologists proposing the collar was sold near a house associated with the word in London, and others suggesting the elaborate, fussy nature of the collar suggested a kind of vanity-peccadillo. Whether or not the connection is genuine, Piccadilly in London — the famous street and circus — is believed by many etymologists to derive from this 'piccadill' collar, making peccadillo a possible ancestor of one of the world's most famous addresses.

In modern English, peccadillo is used with consistent lightness — it always implies that the offense in question is minor, that the speaker is not truly condemning it. 'His peccadilloes were well known but universally tolerated.' The word performs a social function: it allows an accusation to be made while simultaneously signaling that the accusation is not serious. This is a sophisticated rhetorical maneuver for a single noun to accomplish, and the diminutive built into the Spanish original is exactly what enables it.