1) to be pleased together with, to approve together (with others)
2) to be pleased at the same time with, consent, agree to
2a) to applaud
Part of Speech: verb
From G4862 and G2106; to think well of in common, that is, assent to, feel gratified with: - allow, assent, be pleased, have pleasure.
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 συνευδοκέω; click on the second column to search for that grammatical form of the root συνευδοκέω; click on the third column to search for that word and grammatical form; click on the total to search for the root συνευδοκέω.