late 14c., "visitor, one who approaches or is lately arrived," agent noun from come. Meaning "one showing promise" is attested from 1879. Phrase all comers "everyone who chooses to come" is recorded from 1560s. Middle English also had comeling "a comer, newcomer, stranger" (mid-13c.), also "stray animal" (c. 1200).
comedo
come-down
comedy
comely
come-outer
comer
comestible
comet
cometh
comeuppance
comfit