Real Dictionary

write up
phrasal verb: If you write up something that has been done or said, you record it on paper in a neat and complete form, usually using notes that you have made.

write up in American English
to put into writing, esp. in full detail
to write a record or account of

write up in British English
to describe fully, complete, or bring up to date in writing
noun: a published account of something, such as a review in a newspaper or magazine

write-up
countable noun: A write-up is an article in a newspaper or magazine, in which someone gives their opinion of something such as a film, restaurant, or new product.

write-up in Accounting
noun: A write-up is the act of doing the trial balance and financial statements at the end of the year.

write-up in American English
a written report or description, as in a newspaper, magazine, etc.; sometimes, specif., a favorable account, as for a publicity release
noun: a written description or account, as in a newspaper or magazine

write-up in British English
noun: a written review of someone or something in a newspaper, magazine, book, etc.