Definition

In a way that shows a lack of loyalty or faithfulness, often in relationships.

Example

He acted unfaithfully by betraying her trust.

Conversation

Did you hear about Mark? He was caught cheating on his girlfriend.

Really? That's so surprising! I thought he was loyal.

Yeah, but apparently he acted unfaithfully for months.

That's just wrong! I can't believe he would do that.

Synonyms & Antonyms

Root Explanation

Unfaithfully → It is formed from "un-" (meaning not) and "faithful" (from Old English "fæðe", meaning loyalty or faithfulness) and "-ly" (meaning in a manner of). The word describes an action done in a manner that is not loyal or faithful.

Memory Tip

Think of 'not' ('un-') being added to 'faithful' — this helps you remember that 'unfaithfully' means acting in a way that lacks loyalty or faith.

Visually Confused Words