sincer- +
(Latin: sound, pure, clean, whole, genuine, untainted)
2. Not genuine and not reflecting true feelings.
2. Without sincerity; hypocritically.
2. Deceitful or hypocritical.
3. Lack of sincerity; hypocrisy; deceitfulness. 4. An instance of being insincere: "She recalled their many past insincerities as a couple."
Motto of Calvin Theological Seminary, Grand Rapids, Michigan, USA.
2. Based on what is truly and deeply felt.
3. Free of deceit, hypocrisy, or falseness; earnest: "He wrote a sincere apology for his actions."
4. A sincere effort to improve; a sincere friend.
5. Pure; unmixed; unadulterated.
Theories of the etymology of sincere
Several theories have been advanced to explain the derivation of the word sincere, but none has been substantiated!
The most logical attributes the genesis of the word to the Latin sincerus, meaning "pure" or "clean"; but, many etymologists state that sincere is a compounding of sine cera, which means "without wax".
According to this "folk etymology", in the time of the ancient Romans, devious dealers in marble and pottery would conceal defects in their products by filling the cracks and holes with wax.
Honest merchants, who did not doctor their products, proudly displayed their wares as being without wax; that is, they were sine cera.
It is unlikely that this is the origin of sincere; at any rate, accepting this theory should alert us to not forget another Latin phrase: caveat emptor!
Another "origin" of sincere
This sneaky trick (rubbing wax into the cracks of marble works) came to the attention of the Roman Senate, which passed a law stating that all marble purchased by the government must be sine cera, "without wax".
From this law and this root, comes our modern word sincere, which means "without deceit".
One more theory of the origin of sincere
Modern scholars do not accept the dubious account about sincere originally meaning "without wax".
The present belief is that the Latin sincerus, which became sincere in English, came from sine, "without", and some lost word that was akin to caries, "decay".
It would thus be synonymous with the Greek akeratos, "without taint".
2. A written formula for ending a letter; such as, "Yours sincerely" is often used immediately before the signature at the end a letter or e-mail, which is addressed to somebody by name; another example, "Sincerely yours, Jim Mason".
2. Being without hypocrisy or pretense; true: "He expressed his sincerest hope for her recovery from the illness.
2. A quality of naturalness and simplicity.
3. An earnest, genuine, and sincere feeling.