Read the dictionary definition of suck. All definitions for this word.
1. the act of sucking
2. draw into the mouth by creating a practical vacuum in the mouth
1. suck the poison from the place where the snake bit
2. suck on a straw
3. the baby sucked on the mother's breast
3. give suck to
1. The wetnurse suckled the infant
2. You cannot nurse your baby in public in some places
4. take in, also metaphorically
1. The sponge absorbs water well
2. She drew strength from the minister's words
5. draw something in by or as if by a vacuum
1. Mud was sucking at her feet
6. provide sexual gratification through oral stimulation
7. be inadequate or objectionable
1. this sucks!
2. this blows!
8. attract by using an inexorable force, inducement, etc.
1. The current boom in the economy sucked many workers in from abroad
See also: Merriam-Webster definition of suck