1) hard, harsh, rough, stiff
1a) of men: metaphorically harsh, stern, hard
1b) of things: violent, rough, offensive, intolerable
Part of Speech: adjective
Citing in TDNT: 5:1028, 816
From the base of G4628; dry, that is, hard or tough (figuratively harsh, severe): - fierce, hard.
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 σκληρός; click on the second column to search for that grammatical form of the root σκληρός; click on the third column to search for that word and grammatical form; click on the total to search for the root σκληρός.