Kamsin \Kam*sin"\, Khamsin \Kham*sin"\, n. [Ar. khams[=i]n, fr. khams[=u]n, oblique case khams[=i]n, fifty; -- so called because it blows for about fifty days, from April till June.] A hot southwesterly wind in Egypt, coming from the Sahara. [Written also {Khamseen}.]