Today, while eh has many different uses, it is most popularly used in a manner similar in meaning to "Excuse me?", "Please repeat that", "Huh?", or to otherwise mark a question.

EH meaning: 1. used to express surprise or confusion, to ask someone to repeat what they have said, or as a way…. Learn more.

The meaning of EH is —used to ask for confirmation or repetition or to express inquiry—used especially in Canadian English in anticipation of the listener's or reader's agreement.

Eh is used in writing to represent a noise that people make as a response in conversation, for example to express agreement or to ask for something to be explained or repeated.

Definition of eh exclamation in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

an exclamation used to express questioning surprise or to seek the repetition or confirmation of a statement or question: Eh? What did you say?.

There are four meanings listed in OED's entry for the interjection eh, one of which is labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.