Adjective sincere has 2 senses
- sincere - open and genuine; not deceitful; "he was a good man, decent and sincere"; "felt sincere regret that they were leaving"; "sincere friendship"
Antonyms: insincere, bootlicking, fawning, obsequious, sycophantic, toadyish, buttery, fulsome, oily, oleaginous, smarmy, unctuous, dissembling, dissimulating, dissimulative, false, hollow, gilded, meretricious, specious, hypocritical, feigned
- earnest, in earnest, sincere, solemn - characterized by a firm and humorless belief in the validity of your opinions; "both sides were deeply in earnest, even passionate"; "an entirely sincere and cruel tyrant"; "a film with a solemn social message"
Antonym: frivolous (indirect, via serious)
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