1) a forerunner
1a) especially one who is sent before to take observations or act as a spy, a scout, a light armed soldier
1b) one who comes in advance to a place where the rest are to follow
Part of Speech: adjective
Citing in TDNT: 8:235, 1189
From the alternate of G4390; a runner ahead, that is, scout (figuratively precursor): - forerunner.
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 πρόδρομος; click on the second column to search for that grammatical form of the root πρόδρομος; click on the third column to search for that word and grammatical form; click on the total to search for the root πρόδρομος.