Available Definitions:
1) superl. - Pure; unmixed; unadulterated.
2) superl. - Whole; perfect; unhurt; uninjured.
3) superl. - Being in reality what it appears to be; having a character which corresponds with the appearance; not falsely assumed; genuine; true; real; as, a sincere desire for knowledge; a sincere contempt for meanness.
4) superl. - Honest; free from hypocrisy or dissimulation; as, a sincere friend; a sincere person.