C2[I or T]to pull in liquid or air through your mouth without using your teeth, or to move the tongue and muscles of the mouth around something inside your mouth, often in order to dissolve it: She was sitting on the grass sucking lemonade through a straw.I sucked my thumb until I was seven.I tried sucking (on) a mint to stop myself coughing.They used to give you sweets to suck on in planes to stop your ears from going pop.Biting, chewing and swallowingEating›[T+ adv/prep]Something that sucks a liquid or an object in a particular direction pulls it with great force: The waves came crashing over my head and I could feel myself being sucked under by the currents.figurativeContinued rapid growth in consumer spending will suck in(= encourage) more imports.Pulling