write off

v. disregard an outstanding debt (as of a customer); consider worthless; make a reduction in a value for accounting purposes

n. cancellation from an account of a worthless asset (Finance); something which is entirely useless

A write-off may refer to either an accounting write-off or an income tax write-off. It is also a term commonly used in vehicle insurance to describe a vehicle which is cheaper to replace than to repair, known in the U.S. as being a totaled car.
See more at Wikipedia.org...

Verb
1. concede the loss or worthlessness of something or somebody; "write it off as a loss"
(hypernym) admit, acknowledge
2. write something fluently, and without hesitation
(hypernym) write, compose, pen, indite
3. cancel (a debt)
(hypernym) cancel, strike down
(derivation) write-off
4. reduce the estimated value of something; "For tax purposes you can write off the laser printer"
(synonym) write down
(hypernym) depreciate
(derivation) write-off, write-down

Noun
1. (accounting) reduction in the book value of an asset
(synonym) write-down
(hypernym) depreciation, wear and tear
(hyponym) tax write-off, tax deduction, deduction
(derivation) write off, write down
(classification) accounting
2. the act of cancelling from an account a bad debt or a worthless asset
(hypernym) cancellation
(derivation) write off

Charging an asset amount to expense or loss, for example through the use of depreciation and amortization of assets.

An adjustment to the value of loans recorded in the balance sheets of MFIs. A loan is written off when it is considered to be totally unrecoverable, and is removed from the balance sheet.
See also:
 write-down