vacillate
verb [intransitive] (formal)to keep changing your opinion or thoughts about something, especially in a way that annoys other people 观点（或立场等）摇摆；动摇 The country’s leaders are still vacillating between confrontation and compromise. 该国领导人仍在对抗和妥协之间摇摆不定。
Word Originlate 16th cent. (in the sense ‘sway unsteadily’): from Latin vacillat- ‘swayed’, from the verb vacillare.