drop by the wayside vs throw in

drop by the wayside and throw in both are verbs.

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

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

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

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

drop by the wayside (verb)	throw in (verb)
give up in the face of defeat of lacking hope; admit defeat	to insert between other elements
	give up in the face of defeat of lacking hope; admit defeat
	add as an extra or as a gratuity