plutonium trigger vs plutonium pit

plutonium trigger and plutonium pit both are nouns.

Word	Noun	Adjective	Verb	Adverb
plutonium trigger	Yes	No	No	No
plutonium pit	Yes	No	No	No

As nouns, plutonium trigger and plutonium pit are synonyms defined as:

plutonium trigger and plutonium pit: a steel or beryllium sphere containing plutonium 239 that triggers nuclear fission when compressed by explosives

plutonium trigger (noun)	plutonium pit (noun)
a steel or beryllium sphere containing plutonium 239 that triggers nuclear fission when compressed by explosives	a steel or beryllium sphere containing plutonium 239 that triggers nuclear fission when compressed by explosives