1) to bear witness with, bear joint witness
Part of Speech: verb
Citing in TDNT: 4:508, 564
From G4862 and G3140; to testify jointly, that is, corroborate by (concurrent) evidence: - testify unto, (also) bear witness (with).
|testify in support||33.266|
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 συμμαρτυρέω; click on the second column to search for that grammatical form of the root συμμαρτυρέω; click on the third column to search for that word and grammatical form; click on the total to search for the root συμμαρτυρέω.