feeling vs first blush

feeling and first blush both are nouns.

Word	Noun	Adjective	Verb	Adverb
feeling	Yes	No	No	No
first blush	Yes	No	No	No

As nouns, first blush is a hyponym of feeling; that is, first blush is a word with a more specific, narrower meaning than feeling:

Other hyponyms of feeling include presence, effect, hunch, intuition, suspicion.

feeling (noun)	first blush (noun)
the experiencing of affective and emotional states	at the first glimpse or impression
an intuitive understanding of something
a physical sensation that you experience
the sensation produced by pressure receptors in the skin
a vague idea in which some confidence is placed
the general atmosphere of a place or situation and the effect that it has on people