language unit vs string

language unit and string both are nouns.

Word	Noun	Adjective	Verb	Adverb
language unit	Yes	No	No	No
string	Yes	No	Yes	No

language unit (noun)	string (noun)
one of the natural units into which linguistic messages can be analyzed	a lightweight cord
	a tie consisting of a cord that goes through a seam around an opening
	a necklace made by stringing objects together
	a tightly stretched cord of wire or gut, as a part of an instrument or a tennis racket
	a collection of things threaded on a single strand, or as if threaded on a single strand
	stringed instruments that are played with a bow
	a linear sequence (as of characters, words, proteins, etc.)
	a sequentially ordered set of things or events or ideas in which each successive member is related to the preceding
	(cosmology) a hypothetical one-dimensional subatomic particle having a concentration of energy and the dynamic properties of a flexible loop
	a tough piece of fiber in vegetables, meat, or other food (especially the tough fibers connecting the two halves of a bean pod)

language unit (verb)	string (verb)
	add as if on a string
	provide with strings
	thread on or as if on a string
	remove the stringy parts of
	string together; tie or fasten with a string
	stretch out or arrange like a string
	move or come along