I. ˈsēˌsȯ noun
Etymology: probably reduplication of saw (III)
1. : an alternating up-and-down or backward-and-forward motion or movement ; specifically : a contest or struggle in which now one side now the other has the lead
warfare … has been a continuing seesaw between the offensive and the defensive — S.L.A.Marshall
2.
a. : a game in which two children or groups of children ride on opposite ends of a plank or similar piece balanced in the middle so that one end goes up as the other goes down
b. : an apparatus (as a long plank or piece set on a center mount) improvised or manufactured for use in the game of seesaw — called also teeter-totter
II. intransitive verb
1.
a. : to move backward and forward or up and down
planes could not land on the seesawing box-top flight deck at night — Wirt Williams
b. : to play at seesaw
2. : alternate
it seesaws between biography and criticism — J.L.Davis
the lead seesawed between the two runners right up to the finish line
transitive verb
: to cause to move in seesaw fashion
seesawed her skywards — Israel Zangwill
III. adjective
: moving up and down or to and fro : having a reciprocating motion : reciprocal
the seesaw nature of the war during its early stages — Greg MacGregor