pen ‧ du ‧ lum /ˈpendjələm, ˈpendjʊləm $ -dʒə-/ BrE AmE noun [countable]
[ Date: 1600-1700 ; Language: Modern Latin ; Origin: Latin pendulus ; ⇨ ↑ pendulous ]
1 . a long metal stick with a weight at the bottom that swings regularly from side to side to control the working of a clock
2 . the pendulum used to talk about the tendency of ideas, beliefs etc to change regularly to the opposite:
After several years of Republican government, the pendulum will undoubtedly swing back and voters will elect a Democrat.
the pendulum of
the pendulum of fashion