yo-yo
noun
1
a fool US, 1955.
2
a bisexual US, 1986.
3
a hot rod enthusiast who races illegally US, 1956.
4
in air combat, a steep climb and dive in an attempt to gain a more favourable position US, 1989.► up and down like a yo-yoused of a person whose moods alternate rapidly between optimism and despair UK, 1984