Synonyms for Seesaw (same or very similar meaning)
WordNet sense 1 (a plaything consisting of a board balanced on a fulcrum; the board is ridden up and down by children at either end):
teeter, teeter-totter, teeterboard, dandle board, tilting boardWordNet sense 2 (move unsteadily, with a rocking motion):
totterFrom the ODE community, based on WordNetadd/edit