peccadillo

noun, plural pec·ca·dil·loes, pec·ca·dil·los.

1. a very minor or slight sin or offense; a trifling fault.

noun plural -loes or -los

1. a petty sin or trifling fault

n.“slight sin,” 1590s (earlier in corrupt form peccadilian, 1520s), from Spanish pecadillo, diminutive of pecado “a sin,” from Latin peccatum “a sin, fault, error,” noun use of neuter past participle of peccare “to miss, mistake, make a mistake, do amiss; transgress, offend, be licentious, sin,” perhaps literally “to stumble,” from a PIE verbal root *ped- “to walk, stumble, fall,” related to the root of foot (n.).