(n)luck, fortune, chance, hazardan unknown and unpredictable phenomenon that causes an event to result one way rather than another“bad luck caused his downfall”, “we ran into each other by pure chance”
(v)guess, venture, pretend, hazardput forward, of a guess, in spite of possible refutation“I am guessing that the price of real estate will rise again”, “I cannot pretend to say that you are wrong”