pull back vs pullback

pull back is not a noun while pullback is a noun.

Word	Noun	Adjective	Verb	Adverb
pull back	No	No	Yes	No
pullback	Yes	No	No	No

pull back (noun)	pullback (noun)
	(military) the act of pulling back (especially an orderly withdrawal of troops)
	a device (as a decorative loop of cord or fabric) for holding or drawing something back

pull back (verb)	pullback (verb)
make a retreat from an earlier commitment or activity
move to a rearward position; pull towards the back
stretch back a bowstring (on an archer's bow)
use a surgical instrument to hold open (the edges of a wound or an organ)
pull back or move away or backward