n. 1 a wind in S. Asia, esp. in the Indian Ocean, blowing from the south west in summer (wet monsoon) and the north east in winter (dry monsoon). 2 a rainy season accompanying a wet monsoon. 3 any other wind with periodic alternations. monsoonal adj.
[ obs. Du. monssoen f. Port. monç°.o f. Arab. mawsim fixed season f. wasama to mark ]