fill in

fill in
phrasal verb
Word forms "fill in":
present tense I/you/we/they fill in he/she/it fills in present participle filling in past tense filled in past participle filled in
1) [transitive] to add information such as your name or address in the empty spaces on an official document

Please fill in your name and address in the space provided.

I spent over two hours filling in the application form.

Fill in the missing words.

fill in the blanks (= to give or learn information that is needed in order to understand something properly):

We know roughly how the system works, but Brian is here to fill in the blanks.

2) [transitive]
same as fill I, 3)

The canal is now disused and partly filled in.

3) fill someone in
[transitive] informal to give someone details about something

Did Sam fill you in about the new project?

My secretary will fill you in on the details.

4) [intransitive] to do someone's job for them while they are away
fill in for:

I'm filling in for the receptionist at the moment.

English dictionary. 2014.