write down

(noun) (accounting) reduction in the book value of an asset. Synonyms: write-off, write-down.

(verb) put down in writing; of texts, musical compositions, etc.. Synonyms: write down, set down, get down, put down.

(verb) reduce the estimated value of something. Synonyms: expense, write off, write down. Example: "For tax purposes you can write off the laser printer."