1) a fellow heir, a joint heir
2) one who obtains something assigned to himself with others, a joint participant
Part of Speech: noun masculine
Citing in TDNT: 3:767 & 7:787, 442 & 1102
From G4862 and G2818; a co-heir, that is, (by analogy) participant in common: - fellow (joint) -heir, heir together, heir with.
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 συγκληρονόμος; click on the second column to search for that grammatical form of the root συγκληρονόμος; click on the third column to search for that word and grammatical form; click on the total to search for the root συγκληρονόμος.