while vs cold snap

while and cold snap both are nouns.

Word	Noun	Adjective	Verb	Adverb
while	Yes	No	No	No
cold snap	Yes	No	No	No

As nouns, cold snap is a hyponym of while; that is, cold snap is a word with a more specific, narrower meaning than while:

while: a period of indeterminate length (usually short) marked by some action or condition
cold snap: a period of cold weather

Other hyponyms of while include cold spell, hot spell, snap.

while (noun)	cold snap (noun)
a period of indeterminate length (usually short) marked by some action or condition	a period of cold weather