clotting time vs time period

clotting time and time period both are nouns.

Word	Noun	Adjective	Verb	Adverb
clotting time	Yes	No	No	No
time period	Yes	No	No	No

As nouns, time period is a hypernym of clotting time; that is, time period is a word with a broader meaning than clotting time:

clotting time: the time it takes for a sample of blood to clot; used to diagnose some clotting disorders
time period: an amount of time

Other hypernyms of clotting time include period, period of time.

clotting time (noun)	time period (noun)
the time it takes for a sample of blood to clot; used to diagnose some clotting disorders	an amount of time