ˈreɪnɪ adj. (rainier, rainiest) 1 (of weather, a climate, day, region, etc.) in or on whichrain is falling or much rain usually falls. 2 (of cloud, wind, etc.) laden with or bringing rain. ørainy day a time of specialneed in thefuture. øørainily adv. raininess n. [OE renig (as RAIN)]