1) strong, mighty
1a) of living beings
1a1) strong either in body or in mind
1a2) of one who has strength of soul to sustain the attacks of Satan, strong and therefore exhibiting many excellences
1b) on inanimate things
1b1) strong, violent, forcibly uttered, firm, sure
Part of Speech: adjective
Citing in TDNT: 3:397, 378
From G2479; forcible (literally or figuratively): - boisterous, mighty (-ier), powerful, strong (-er, man), valiant.
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 ἰσχυρός; click on the second column to search for that grammatical form of the root ἰσχυρός; click on the third column to search for that word and grammatical form; click on the total to search for the root ἰσχυρός.