also: しんし
noun
pendulum
Refers to a weight suspended from a pivot so that it can swing freely, used in clocks, physics experiments, and figuratively for something that swings back and forth.
振り子時計が部屋の隅で規則正しく動いている。
A pendulum clock is ticking regularly in the corner of the room.
振り子の周期は糸の長さで決まる
The period of a pendulum is determined by the length of the string.
Simplified kanji form, also used. The reading しんし is rare and archaic.
Rare archaic reading for the simplified form. Not used in modern Japanese.
振動 means vibration or oscillation in general, while 振り子 specifically refers to a pendulum.
Compound of 振り (furi, 'swinging') + 子 (ko, diminutive suffix). The reading しんし is a Sino-Japanese reading of the same characters, now obsolete.