seesaw

seesaw is a   Noun

Definition:

[1] A play among children in which they are seated upon the opposite ends of a plank which is balanced in the middle, and move alternately up and down.

[2] A plank or board adjusted for this play.

[3] A vibratory or reciprocating motion. He has been arguing in a circle; there is thus a seesaw between the hypothesis and fact. Sir W. Hamilton.

[4] Same as Crossruff.

Synonyms: