English 'sincere' descends through French from Latin 'sincērus' (pure, unmixed), likely a compound of 'sin-' (one, from PIE *sem-) and an element related to 'crescere' (to grow), meaning 'of one growth' — making it a distant cousin of 'simple,' 'single,' 'same,' and even 'Sanskrit.'
Definition
Free from pretense, deceit, or hypocrisy; proceeding from genuine feelings or convictions, from Latin sincērus meaning clean, pure, or whole, likely composed of sin- (one) and a root related to crēscere (to grow).
The Full Story
Latin1st century BCEwell-attested
TheEnglishword 'sincere' entered the language in the 1530s from the Latin 'sincērus', meaning 'clean, pure, sound, whole, genuine, uninjured'. The Latin term was used by classical authorsincluding Cicero and Horace to describe things that were unadulterated or unmixed — pure honey, pure wine, genuine feeling. The exact etymology of 'sincērus' has been debated since antiquity
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The famous story that 'sincere' comes from Latin 'sine cera' (without wax) — supposedlydescribing honest Roman sculptors who didn't hide marble flaws with wax — has no ancient attestation whatsoever. No Roman writermentions this practice as theword's origin, and the phonology doesn't work: Latin 'sine' compounds don't produce '-ērus' adjectives. The real etymology is stranger: 'sincere' likely means 'of one growth,' connecting it to the same PIE root (*sem-, 'one') that
*sem- ('one, together, as one') combined with a second element related to *ker- ('to grow, to nourish'). The root *sem- is extraordinarily productive across Indo-European languages, yielding Latin 'semel' ('once'), 'similis' ('like, resembling'), Greek 'homos' ('same'), Sanskrit 'sam-' ('together'), and English words like 'same', 'similar', 'simple', 'simultaneous', and 'ensemble'. The root *ker- produced Latin 'crescere' ('to grow'), 'creare' ('to create'), and 'Ceres' (goddess of grain). Thus 'sincērus' likely meant something like 'of one growth' — that is, pure, unmixed, not adulterated by foreign matter. The word passed through Middle French 'sincere' before arriving in English, where it initially described things that were pure or unadulterated before shifting primarily to describe honesty and genuineness of character by the early 17th century. Key roots: sincērus (Latin: "clean, pure, sound, whole, genuine"), *sem- (Proto-Indo-European: "one, together, as one"), *ker- (Proto-Indo-European: "to grow, to nourish, to feed").