champion, chief, X excel, giant, man, mighty (man, one), strong (man), valiant man

Boyd’s Bible Dictionary:

(sons of Gaea). Huge men—Nephilim, Gibborim (Gen. 6:4); Rephaim (Gen. 14:5); Emim, Anakim, Zuzim (Num. 13:28-33; Deut. 3:11; 1 Sam. 17:4).

Concise Bible Dictionary:

1. gibbor, “mighty, strong,” as the word is often elsewhere translated (Job 16:14).
2. rapha, “a fearful one.” In the plural and with the article it is treated as a proper name, the REPHAIM, or sons of Raphah, a race of giants who lived beyond the Jordan, from whom Og the giant king of Bashan descended. The sons of Raphah were afterward found among the Philistines. At times the term Rephaim applies to any people in Canaan who were of great stature (Deut. 2:11,20; Deut. 3:11,13; Josh. 12:4; Josh. 13:12; Josh. 15:8; Josh. 17:15; Josh. 18:16; 1 Chron. 20:4,6,8). The word Rephaim is untranslated in Genesis 14:5 and Genesis 15:20.
3. raphah, same as rapha (2 Sam. 21:16-22).
4. nephilim. The signification of this word is uncertain: some trace it to a root “to fall,” but then it is not clear whether it signifies “fallen ones,” or “those who fall upon.” They were men of great stature, which made the Israelites consider themselves as grasshoppers in comparison. They are not said (as has been supposed) to be the offspring of the sons of God and the daughters of men: those born of them are described as “mighty men (gibborim) which were of old, men of renown.” The nephilim are merely said to be “in the earth in those days,” and they were also seen by the spies about a thousand years afterward: this is all that is revealed respecting them. The various ancient versions confirm the translation of “giants” (Gen. 6:4; Num. 13:33).

Strong’s Dictionary of Hebrew Words:

Transliteration:
gibbowr
Phonic:
ghib-bore’
Meaning:
or (shortened) gibbor {ghib-bore'}; intensive from the same as 1397; powerful; by implication, warrior, tyrant
KJV Usage:
champion, chief, X excel, giant, man, mighty (man, one), strong (man), valiant man