1
- 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跷跷板。
1.1
- figurative a situation characterized by rapid, repeated changes from one state or condition to another〈喻〉忽起忽落; 变幻无常：
the emotional see-saw of a first love affair
初恋心情的变幻无常
as modifier see-saw interest rates.忽起忽落的利率。
no obj.
1- change rapidly and repeatedly from one position, situation, or condition to another and back again变化不定; 忽起忽落：
the market see-sawed as rumours spread of an imminent cabinet reshuffle.
由于传闻内阁即将改组, 市场因而起伏不定。
1.1
- with obj. cause (something) to move back and forth or up and down rapidly and repeatedly使前后来回移动; 使起伏不定：
Sybil see-sawed the car back and forth.
西比尔将车前后来回地开着。
词源
mid 17th cent. (originally used by sawyers as a rhythmical refrain)： reduplication of the verb SAW1 (symbolic of the sawing motion).