v.tr.1. a.  To draw (liquid) into the mouth by movements of the tongue and lips that create suction.
b.  To draw a liquid into the mouth through or from: a baby sucking a bottle.
c.  To hold, moisten, or maneuver (a sweet, for example) in the mouth, especially in creating suction.
 2. a.  To draw in by establishing a partial vacuum: a cleaning device that sucks up dirt; sucked air into his lungs.
b.  To draw in a current in a fluid: debris that got sucked into the drain.
c.  To cause to be involved or engaged in something: teenagers who are sucked into a life of crime.
 3.  Vulgar Slang   To perform fellatio on.
 v.intr.1.  To move the tongue and lips to create suction: sucked on a straw.
2.  To draw something in by suction: The pump started to suck.
3.  To draw nourishment from a breast or teat; suckle.
4.  To make a sound caused by suction.
5.  Slang  a.  To be highly unpleasant or disagreeable: This job sucks.
b.  To be of poor or inferior quality: The acting in that movie sucked.
c.  To be inept: I suck at math.