fall by the wayside vs throw in the towel

fall by the wayside and throw in the towel both are verbs.

Word	Noun	Adjective	Verb	Adverb
fall by the wayside	No	No	Yes	No
throw in the towel	No	No	Yes	No

As verbs, fall by the wayside and throw in the towel are synonyms defined as:

fall by the wayside and throw in the towel: give up in the face of defeat of lacking hope; admit defeat

Other synonyms of fall by the wayside include chuck up the sponge, drop by the wayside, drop out, give up, quit, throw in.

fall by the wayside (verb)	throw in the towel (verb)
give up in the face of defeat of lacking hope; admit defeat	give up in the face of defeat of lacking hope; admit defeat