to keep papers, documents etc in a particular place so that you can find them easily:
The contracts are filed alphabetically.
file something under something
I looked to see if anything was filed under my name.
file something away
The handbooks are filed away for future reference.
to give or send an official report or news story to your employer:
The officer left the scene without filing a report.
3 [intransitive always + adverb/preposition, transitive] law
to give a document to a court or other organization so that it can be officially recorded and dealt with
file a complaint/lawsuit/petition etc (against somebody)
Mr Genoa filed a formal complaint against the department.
4 [intransitive always + adverb/preposition]
if people file somewhere, they walk there in a line:
We began to file out into the car park.
The mourners filed past the coffin.
5 [intransitive always + adverb/preposition, transitive]TZD
to use a metal or wooden tool to rub something in order to make it smooth:
File down the sharp edges.
She sat filing her nails.