suck up verb 3/ˈsʌkˌʌp/ noun 1forms 4 verb3 •To absorb (fluid).The dry soil sucked up water like a sponge. •(slang) To adulate or flatter (someone) excessively, generally to obtain some personal benefit or favour.Jimmy sucked up to the English teacher hoping he would get an A. •(slang, vulgar) To fellate (someone). suck-up /ˈsʌkˌʌp/ noun1 •(informal, disapproving) A person who sucks up, or plays up through adulation or flattery or other such devices to win another's favour; a brown-noser.Dulcie was already holding Lidiaʼs hand, and she didnʼt even know her! What a suck-up. — 2005 formssucked up · sucking up · sucks up · suck-ups