sucking

Not yet weaned.

The application of suction to an object by the mouth.

• s. drive — instinctive enthusiasm of the neonate to suck on a teat, or any object which even remotely resembles a teat.
• s. lice — lice in the order Anoplura. Includes the families Echinophthiriidae, Haematopinidae, Hoplopleuridae, Lignognathidae and Pediculidae.
• s. reflex — sucking movements of the lips of newborn and unweaned animals elicited by placing a warm, fleshy mass in the animal's mouth.

The noun has one meaning:

Meaning #1: the act of sucking
  Synonyms: suck, suction