alarm clock vs clock

alarm clock and clock both are nouns.

Word	Noun	Adjective	Verb	Adverb
alarm clock	Yes	No	No	No
clock	Yes	No	Yes	No

As nouns, clock is a hypernym of alarm clock; that is, clock is a word with a broader meaning than alarm clock:

alarm clock (noun)	clock (noun)
a clock that wakes a sleeper at some preset time	a timepiece that shows the time of day

alarm clock (verb)	clock (verb)
	measure the time or duration of an event or action or the person who performs an action in a certain period of time