1) a trembling or quaking with fear
2) with fear and trembling, used to describe the anxiety of one who distrusts his ability completely to meet all requirements, but religiously does his utmost to fulfil his duty
Part of Speech: noun masculine
From G5141; a "trembling", that is, quaking with fear: - + tremble (-ing).
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 τρόμος; click on the second column to search for that grammatical form of the root τρόμος; click on the third column to search for that word and grammatical form; click on the total to search for the root τρόμος.