/ ˈvæsəleɪt; NAmE / verb
[ v ] ( formal ) to keep changing your opinion or thoughts about sth, especially in a way that annoys other people
SYN waver
► va·cil·la·tion / ˌvæsəˈleɪʃn; NAmE / noun [ U , C ]
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WORD ORIGIN
late 16th cent. (in the sense sway unsteadily ): from Latin vacillat- swayed, from the verb vacillare .