Meaning of “write sth off” - Learner’s Dictionary

write sth off

phrasal verb with write uk us /raɪt/ verb (past tense wrote, past participle written)

to accept that an amount of money has been lost or will never be paid to you:

to write off debts

to damage a vehicle so badly that it cannot be repaired

(Definition of “write sth off” from the Cambridge Learner’s Dictionary © Cambridge University Press)