retire vs retreat

retire is not a noun while retreat is a noun.

Word	Noun	Adjective	Verb	Adverb
retire	No	No	Yes	No
retreat	Yes	No	Yes	No

As verbs, retire and retreat are synonyms defined as:

Other synonyms of retire include draw back, move back, pull away, pull back, recede, withdraw.

As verbs, retreat is a hyponym of retire; that is, retreat is a word with a more specific, narrower meaning than retire:

Other hyponyms of retire include fall back, retrograde, back down, back off, back up.

retire (noun)	retreat (noun)
	(military) withdrawal of troops to a more favorable position to escape the enemy's superior forces or after a defeat
	withdrawal for prayer and study and meditation
	the act of withdrawing or going backward (especially to escape something hazardous or unpleasant)
	an area where you can be alone
	(military) a bugle call signaling the lowering of the flag at sunset
	(military) a signal to begin a withdrawal from a dangerous position
	a place of privacy; a place affording peace and quiet

retire (verb)	retreat (verb)
prepare for sleep	make a retreat from an earlier commitment or activity
cause to get out	pull back or move away or backward
cause to be out on a fielding play	move back
lose interest	move away, as for privacy
pull back or move away or backward
dispose of (something no longer useful or needed)
break from a meeting or gathering
go into retirement; stop performing one's work or withdraw from one's position
withdraw from active participation
make (someone) retire
withdraw from circulation or from the market, as of bills, shares, and bonds