unconvincing

US /ˌʌn.kənˈvɪn.sɪŋ/
UK /ˌʌn.kənˈvɪn.sɪŋ/
1.

không thuyết phục

If an explanation or story is unconvincing, it does not sound or seem true or real:

:
They gave some unconvincing explanations for the system failure.