define seasick
seasick adjective. âº âvomiting or having the âfeeling you will âvomit because of the âmovement of the âship you are âtravelling in: I was/âfelt seasick, so I went up on âdeck for some âfresh âair. seasickness noun [U] uk us /-ËsÉªk.nÉs/. noun [U] uk us /-ËsÉªk.nÉs/.