One who, or that which, sucks; esp., one of the organs by which certain animals, as the octopus and remora, adhere to other bodies.
- One that sucks, especially an unweaned domestic animal.
- Informal One who is easily deceived; a dupe.
- Informal One that is indiscriminately attracted to something specified: "The nation's capital is a sucker for a symbolic gesture” ( Jonathan Alter).
- Slang An unspecified thing. Used as a generalized term of reference, often as an intensive: "our goal of getting that sucker on the air before old age took the both of us” ( Linda Ellerbee).
- Slang A person. Used as a generalized term of reference, often as an intensive: He's a mean sucker.
- A lollipop.
- A piston or piston valve, as in a suction pump or syringe.
- A tube or pipe, such as a siphon, through which something is sucked.
- Any of numerous chiefly North American freshwater fishes of the family Catostomidae, having a toothless jaw and a thick-lipped mouth adapted for feeding by suction.
- Zoology An organ or other structure adapted for sucking nourishment or for clinging to objects by suction.
- Botany A secondary shoot produced from the base or roots of a woody plant that gives rise to a new plant.
- To strip suckers or shoots from (plants).
- Informal To trick; dupe: sucker a tourist into a confidence game.
- Botany To send out suckers or shoots.