draw into the mouth by creating a practical vacuum in the mouth; "suck the poison from the place where the snake bit"; "suck on a straw"; "the baby sucked on the mother's breast"
draw something in by or as if by a vacuum; "Mud was sucking at her feet"
attract by using an inexorable force, inducement, etc.; "The current boom in the economy sucked many workers in from abroad"
a never-ending cycle of activities and events (especially when they seem to have little purpose); "if we lose the election the whole legislative merry-go-round will have to start over"