What is the meaning of Fiend?

A devil or demon; a malignant or diabolical being; an evil spirit.

A very evil person.

An enemy; a foe.

The enemy of mankind, specifically, the Devil; Satan.

An addict or fanatic.

To yearn; to be desperate (for something, especially drugs).

Alternative form of feend

dative singular of fēond

nominative and accusative plural of fēond

Source: wiktionary.org