seesaw
名词 seesaw:
a plaything consisting of a board balanced on a fulcrum; the board is ridden up and down by children at either end
同义词:teeter, teeter-totter, teetertotter, teeterboard, tilting board, dandle board
动词 seesaw:
ride on a plank
同义词:teeter-totter, teetertotter
move up and down as if on a seesaw
move unsteadily, with a rocking motion