write off someone/something
— phrasal verb with write us/rɑɪt/verb [ I/T ] past tense wrote /roʊt/, past participle written /ˈrɪt·ən/
(CONSIDER UNIMPORTANT)
to decide that someone or something is not suitable or good enough to be successful:
When he lost the election for governor, some observers wrote him off as a future candidate, but they were proven wrong.