INVESTOPEDIA - Although there may be some superficial similarities between the two concepts, a strict definition of both terms - investing and gambling - reveals the principle differences between them. A standard dictionary defines "invest," as follows: to put (money) to use, by purchase or expenditure, in something offering profitable returns, especially interest or income. The same dictionary defines "gamble" as follows: To play at any game of chance for stakes. To stake or risk money, or anything of value, on the outcome of something involving chance; bet; wager.