SURFACE › having a regular surface that has no holes or lumps in it: soft, smooth skin a smooth wooden table
SUBSTANCE › A substance that is smooth has no lumps in it: Mix the butter and sugar together until smooth.
MOVEMENT › happening without any sudden movements or changes: The plane made a smooth landing.
PROCESS › happening without problems or difficulties: Her job is to help students make a smooth transition from high school to college.
PERSON › too polite and confident in a way that people do not trust: a smooth salesman smoothness noun [U]