worry vs eat on

worry is a noun but eat on is not a noun.

Word	Noun	Adjective	Verb	Adverb
worry	Yes	No	Yes	No
eat on	No	No	Yes	No

As verbs, eat on is a hyponym of worry; that is, eat on is a word with a more specific, narrower meaning than worry:

worry: disturb the peace of mind of; afflict with mental agitation or distress
eat on: worry or cause anxiety in a persistent way

Other hyponyms of worry include misgive, eat, nag.

worry (noun)	eat on (noun)
something or someone that causes anxiety; a source of unhappiness
a strong feeling of anxiety

worry (verb)	eat on (verb)
lacerate by biting	worry or cause anxiety in a persistent way
touch or rub constantly
be worried, concerned, anxious, troubled, or uneasy
disturb the peace of mind of; afflict with mental agitation or distress
be concerned with
be on the mind of