1. (向公司或机构)去函，发信
If you write off to a company or organization, you send them a letter, usually asking for something.

2. 勾销，注销(债务或已花费的款项)
If someone writes off a debt or an amount of money that has been spent on a project, they accept that they are never going to get the money back.

3. 认定…不重要(或无用)；忽视
If you write someone or something off, you decide that they are unimportant or useless and that they are not worth further serious attention.

4. (发生撞车后)将(车辆)报废
If someone writes off a vehicle, they have a crash in it and it is so badly damaged that it is not worth repairing.

5. 取消(计划或项目)
If you write off a plan or project, you accept that it is not going to be successful and do not continue with it.

6. see also: write-off

1. reduce the estimated value of something

e.g. For tax purposes you can write off the laser printer

Synonym: expensewrite down

2. concede the loss or worthlessness of something or somebody

e.g. write it off as a loss

3. write something fluently, and without hesitation

4. cancel (a debt)