Strong's #2389: chazaq (pronounced khaw-zawk')
 from 2388; strong (usu. in a bad sense, hard, bold, violent):--harder, hottest, + impudent, loud, mighty, sore, stiff(-hearted), strong(-er).
Brown-Driver-Briggs Hebrew Lexicon:
 
  châzâq 
 
 1) strong, stout, mighty
 
 1a) strong
 
 1a1) severe, sharp, hot
 1a2) firm, hard
 
 1b) a strong one (substantive)
 
  Part of Speech: adjective
Relation: from H2388
Usage:
This word is used 57 times:
Ezekiel 20:33: "the Lord GOD, surely  with a mighty hand, and with a stretched out"
Ezekiel 20:34: "you out of the countries wherein ye are scattered,  with a mighty and with a stretched out arm,"
Ezekiel 26:17: "the renowned which wast  strong in the sea, she and her inhabitants,"
Ezekiel 30:22: "his arms,  the strong, and that which was broken; and I will cause the sword to fall"
Ezekiel 34:16: "that which was sick: the fat  and the strong; I will feed them with judgment."
Daniel 9:15: "hast brought thy people forth out of the land of Egypt  with a mighty hand,"
Amos 2:14: "Therefore the flight shall perish from the swift,  and the strong shall not strengthen his force,"