Put in

Put in

Transitive phrasal verb of put, meaning to spend a particular amount of time doing something, or to make a particular amount of effort in order to do something:

Wendy has been putting in more hours at the office recently.

They must have put in a lot of work to achieve such an interesting exhibition.

There are other meanings:

http://www.macmillandictionary.com/dictionary/british/put-in#put-in__1