What Does Suck Mean?

When used as a transitive verb the term suck means drawing (liquid) into the mouth, that is, via movements of both the tongue and lips which creates suction. It may also mean drawing in by the establishment of a partial vacuum. It could also mean drawing in either by or as if by means of a current in a fluid. It may mean drawing or pulling as if by suction. The term may be used to mean drawing nourishment either through or from. It could mean holding, moistening, or manoeuvring (a candy, for instance) in the mouth. It is also often used as a vulgar slang in reference to performing fellatio.

When used as an intransitive verb it means drawing or pulling something in by or as if via suction. When used as a synonym for suckle it means drawing nourishment. It could refer to making a sound which is caused by suction.

In vulgar slang terms it means being repulsively disagreeable or offensive. Used as a noun it refers to either the act or to the sound of sucking. It may also be used as another word for auction. The term may also mean 'something drawn in through sucking'.

To hold on to something with your mouth or Usage of somethings else.

Suck means that if you are saying suck. You are saying "they suck their thumb all the time.