Clock pendulum and Compound pendulum

Clock pendulum noun - A physical pendulum used to regulate a clockwork mechanism.

Compound pendulum and clock pendulum are semantically related. In some cases you can use "Compound pendulum" instead a noun phrase "Clock pendulum".

Compound pendulum noun - Pendulum consisting of an actual object allowed to rotate freely around a horizontal axis.

Clock pendulum and compound pendulum are semantically related. Sometimes you can replace phrase "Clock pendulum" with "Compound pendulum", this phrases are similar.