1 (used about a person) really meaning or believing what you say; not pretending （指人）真诚的，诚实的: Do you think she was being sincere when she said she admired me? 她说仰慕我，你觉得她说的是真话吗？

2 (used about a person's feelings, beliefs or behaviour) true; showing what you really mean or feel （指人的感情、信念或行为）真实的，真心的: Please accept our sincere thanks/apologies. 我们竭诚致谢╱道歉，恳请接受。 [OPP] insincere 反义词为insincere➔sincerely adv I am sincerely grateful to you for all your help. 我衷心感谢你的帮助。Yours sincerely, ...(= at the end of a formal letter) 敬启（正式书信末的客套话） ➔sincerity /sɪnˈserəti ||; sɪnˈsɛrətɪ/ noun [U] [OPP] insincerity 反义词为insincerity