extend vs come

extend is not a noun while come is a noun.

Word	Noun	Adjective	Verb	Adverb
extend	No	No	Yes	No
come	Yes	No	Yes	No

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

extend: stretch out over a distance, space, time, or scope; run or extend between two points or beyond a certain point
come: extend or reach

Other hyponyms of extend include radiate, ray, go deep, go far, underrun.

extend (noun)	come (noun)
	the thick white fluid containing spermatozoa that is ejaculated by the male genital tract

extend (verb)	come (verb)
extend one's limbs or muscles, or the entire body	come to pass; arrive, as in due course
thrust or extend out	be found or available
extend in scope or range or area	reach or enter a state, relation, condition, use, or position
lengthen in time; cause to be or last longer	happen as a result
continue or extend	have a certain priority
expand the influence of	come to one's mind; suggest itself
increase in quantity or bulk by adding a cheaper substance	move toward, travel toward something or somebody or approach something or somebody
prolong the time allowed for payment of	be received
use to the utmost; exert vigorously or to full capacity	cover a certain distance
open or straighten out; unbend	reach a destination; arrive by movement or progress
extend or stretch out to a greater or the full length	experience orgasm
cause to move at full gallop	come under, be classified or included
offer verbally	proceed or get along
make available; provide	extend or reach
span an interval of distance, space or time	to be the product or result
reach outward in space	exist or occur in a certain point in a series
stretch out over a distance, space, time, or scope; run or extend between two points or beyond a certain point	be a native of
	to measure up to in kind or quality
	add up in number or quantity
	come forth
	come from; be connected by a relationship of blood, for example