compound pendulum vs pendulum

compound pendulum and pendulum both are nouns.

Word	Noun	Adjective	Verb	Adverb
compound pendulum	Yes	No	No	No
pendulum	Yes	No	No	No

As nouns, pendulum is a hypernym of compound pendulum; that is, pendulum is a word with a broader meaning than compound pendulum:

compound pendulum: pendulum consisting of an actual object allowed to rotate freely around a horizontal axis
pendulum: an apparatus consisting of an object mounted so that it swings freely under the influence of gravity

compound pendulum (noun)	pendulum (noun)
pendulum consisting of an actual object allowed to rotate freely around a horizontal axis	an apparatus consisting of an object mounted so that it swings freely under the influence of gravity