put in

1.  Make a formal offer of, as in a court of law. For example, He put in a plea of not guilty. [Mid-1400s]
2.  Interpose, interject; see put in a good word; put one's oar in.
3.  Spend time at a location or job, as in He put in three years at hard labor, or She put in eight hours a day at her desk. [Mid-1800s]
4.  Plant, as in We put in thirty new trees. [Early 1800s]
5.  Enter a port or harbor, as in The yacht will put in here for the night. [Early 1600s]
6.  put in for. Request or apply for something, as in I put in for a raise, or John put in for department supervisor. [c. 1600]

The verb has 7 meanings:

Meaning #1: introduce
  Synonyms: insert, enclose, inclose, stick in, introduce

Meaning #2: devote (time, effort, etc.) to a task

Meaning #3: keep or lay aside for future use
  Synonyms: store, hive away, lay in, salt away, stack away, stash away

Meaning #4: break into a conversation
  Synonyms: chime in, cut in, butt in, chisel in, barge in, break in

Meaning #5: set up for use
  Synonyms: install, instal, set up

Meaning #6: put on an application, apply for a job, in a competition, etc.
  Synonym: submit

Meaning #7: to insert between other elements
  Synonyms: interject, come in, interpose, throw in, inject