The phrase "eat on" can be understood as a verb that means to worry or cause anxiety in a persistent way. When something "eats on" you, it means that it continuously bothers you or makes you feel uneasy.
In more complex sentences, you might use it to describe situations: - "The uncertainty about my job security is eating on my mind."
While "eat on" specifically refers to worrying, the word "eat" in other contexts generally means to consume food. For example: - "I like to eat pizza." (Here, "eat" means to consume food.)
"Eat on" is a phrase that describes persistent worry or anxiety about something. You can use it when discussing feelings of unease or concern.