spat vs run-in

spat and run-in both are nouns.

Word	Noun	Adjective	Verb	Adverb
spat	Yes	No	Yes	No
run-in	Yes	No	No	No

As nouns, run-in is a hypernym of spat; that is, run-in is a word with a broader meaning than spat:

Other hypernyms of spat include dustup, quarrel, row, words, wrangle.

spat (noun)	run-in (noun)
a young oyster or other bivalve	an angry dispute
a cloth covering (a legging) that covers the instep and ankles
a quarrel about petty points

spat (verb)	run-in (verb)
clap one's hands together
spawn
engage in a brief and petty quarrel
clap one's hands or shout after performances to indicate approval
strike with a sound like that of falling rain
become permanently attached
come down like raindrops