earmark vs marker

earmark and marker both are nouns.

Word	Noun	Adjective	Verb	Adverb
earmark	Yes	No	Yes	No
marker	Yes	No	No	No

As nouns, marker is a hypernym of earmark; that is, marker is a word with a broader meaning than earmark:

Other hypernyms of earmark include mark, marking.

earmark (noun)	marker (noun)
a distinctive characteristic or attribute of someone or something	some conspicuous object used to distinguish or mark something
identification mark on the ear of a domestic animal	a writing implement for making a mark
	a distinguishing symbol

earmark (verb)	marker (verb)
give or assign a resource to a particular person or cause