What does Gideon mean?
From the Hebrew verb gada, 'to hew down, cut off,' hence 'hewer' or 'feller' — fitting the judge who cut down Baal's altar (Judges 6). The common 'mighty warrior' gloss is a secondary association from his role, not the meaning of the root; because no noun is formed from the verb, the exact nuance stays somewhat uncertain.
What does Reuben mean?
Hebrew Re'uven, literally 'behold, a son!' (re'u 'see, behold' + ben 'son'). Genesis 29:32 layers a second biblical wordplay on it: Leah says 'the LORD has looked upon (ra'ah) my affliction' — that play is theological rather than the strict etymology.