Sycophantic /ˌsɪk.əˈfæn.tɪk/: 阿谀奉承的、谄媚的 (of a person | Desvl English Tips

Sycophantic /ˌsɪk.əˈfæn.tɪk/: 阿谀奉承的、谄媚的
(of a person or of behaviour) praising people in authority in a way that is not sincere, usually in order to get some advantage from them
e.g. There was sycophantic laughter from the audience at every one of his terrible jokes.
对应的名词是sycophancy (the character or practices)和sycophant (the person)。