pec·ca·dil·lo \ˌpekəˈdi(ˌ)lō\noun (pluralpeccadilloesorpeccadillos) Etymology: Spanish pecadillo, diminutive of pecado sin, from Latin peccatum, from neuter of peccatus, past participle of peccare to sin : a slight offense : a petty fault < lapses and peccadilloes — Herbert Askwith > < the sexual peccadilloes of a bygone time — Edmund Fuller >