в два раза меньше — two times less
в два раза больше — twice as many / much (as)
в пять раз — five times more, by a factor of five
во второй раз — for the second time
(один) раз — once
два раза — twice
как раз — just, the very
в самый раз — just in time; just right, that's it; to be a perfect fit, to be just one's size
в который раз — once more, once again, yet again
несколько раз — a few times, several times, more than once
лишний раз — one more time