non-committal
From Longman Dictionary of Contemporary Englishnon-committalˌnon-comˈmittal adjective NOT SUREdeliberately not expressing your opinion or intentions clearlynon-committal about The doctor was non-committal about my mother’s chances of recovery. The driver mumbled a non-committal reply.Examples from the Corpusnon-committal• Later he lay in bed beside Anne, trying to think of a satisfactory yet thoroughly non-committal story to tell the police.