see-saw
noun
[ ˈsiːsɔː ]
• a long plank balanced in the middle on a fixed support, on each end of which children sit and swing up and down by pushing the ground alternately with their feet.
see-saw
verb
• change rapidly and repeatedly from one position, situation, or condition to another and back again.
• "the market see-sawed as rumours spread of an imminent cabinet reshuffle"
Origin:
mid 17th century (originally used by sawyers as a rhythmical refrain): reduplication of the verb saw1 (symbolic of the sawing motion).
