1) that which is (has been) filled
1a) a ship inasmuch as it is filled (i.e. manned) with sailors, rowers, and soldiers
1b) in the NT, the body of believers, as that which is filled with the presence, power, agency, riches of God and of Christ
2) that which fills or with which a thing is filled
2a) of those things which a ship is filled, freight and merchandise, sailors, oarsmen, soldiers
2b) completeness or fulness of time
3) fulness, abundance
4) a fulfilling, keeping
Part of Speech: noun neuter
Citing in TDNT: 6:298, 867
From G4137; repletion or completion, that is, (subjectively) what fills (as contents, supplement, copiousness, multitude), or (objectively) what is filled (as container, performance, period): - which is put in to fill up, piece that filled up, fulfilling, full, fulness.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root πλήρωμα; click on the second column to search for that grammatical form of the root πλήρωμα; click on the third column to search for that word and grammatical form; click on the total to search for the root πλήρωμα.