halt vs rein in

halt is a noun but rein in is not a noun.

Word	Noun	Adjective	Verb	Adverb
halt	Yes	Yes	Yes	No
rein in	No	No	Yes	No

As verbs, rein in is a hyponym of halt; that is, rein in is a word with a more specific, narrower meaning than halt:

halt: come to a halt, stop moving
rein in: stop or slow up one's horse or oneself by or as if by pulling the reins

Other hyponyms of halt include go off, pull up short, check, check, check, rein, conk, stall, stall, draw up, haul up, pull up, brake, settle.

halt (noun)	rein in (noun)
an interruption or temporary suspension of progress or movement
the event of something ending
the state of inactivity following an interruption

halt (adjective)	rein in (adjective)
disabled in the feet or legs

halt (verb)	rein in (verb)
stop the flow of a liquid	stop or slow up one's horse or oneself by or as if by pulling the reins
come to a halt, stop moving	stop or check by or as if by a pull at the reins
cause to come to an abrupt stop	control and direct with or as if by reins
stop from happening or developing