The difference between gambler and speculator is that
gambler's expected return is 0 (or minus), the benefit of gambler is the thrill and fun of the process.
speculator is different than gambler in that his expected return is bigger than zero (in other words : odds is on his side)
the line between speculator and investor is murky, but I don't think hedging draws the line. Rather hedging is related with risk aversion. Willing to take high risk does not make that person a gambler.