What Does Wouldn’t Harm a Fly Mean?

Wouldn’t Harm a Fly Meaning

Definition: Very peaceful and nonviolent.

This expression often emphasizes how gentle and kind a person is. A variant of this expression is wouldn’t hurt a fly.

Origin of Wouldn’t Harm a Fly

This expression first appeared in the late 1700s. The idea is that most people would have no problem killing a fly, a widely despised animal.

However, if a person were so incredibly gentle and peaceful, he or she might take pity on a fly and allow it to live. A person who wouldn’t kill a fly is very non-violent, gentle, kind, etc.

Examples of Wouldn’t Harm a Fly

do not harm a flyIn the below dialogue, one friend uses the idiom to describe another friend. This other friend is under suspicion of murder by the police.

Ezekiel: Maggie! Did you hear what happened to Gunther?

Maggie: No. What happened?

Ezekiel: The police arrested him.

Maggie: Oh no! Why?

Ezekiel: They think he murdered someone.

Maggie: That’s ridiculous. Gunther wouldn’t harm a fly, let alone murder someone!

Ezekiel: I know. That’s what I said!

do not harm a flyHere is another example, in which one friend uses the idiom to defend herself from an accusation of violence.

Mila: Hey! How’s it going?

Tyrion: To be honest with you, I’m pretty upset.

Mila: What’s wrong?

Tyrion: I asked you to watch my dog over the weekend.

Mila: And I did. It was a lot of fun!

Tyrion: Did you kick my dog?

Mila: What? Absolutely not! I wouldn’t harm a fly. I would never hurt any living creature, especially not a dog.

Tyrion: Okay. I guess I believe you. It’s just my dog has a big bruise on his side.

More Examples

In this excerpt, a woman describes how kind and gentle a disabled man is. She is emphasizing what a good person he is to explain that she doesn’t believe the police should have shot him six times for a traffic violation.

“He likes the boardwalk,” Ms. Verity said. “He’s very good-hearted. He wouldn’t harm a fly.” –New York Times

This excerpt describes how a murdered man was a very good person who was very peaceful.

There was no nonsense with him. He was no angel, but a great guy. He enjoyed a drink, he worked hard, played hard and lived life like it should be lived. He wouldn’t harm a fly. He was the kind of guy that no doubt would have made the community a better place.”–New York Daily News


The phrase wouldn’t harm a fly is a way to describe a very good hearted person who wouldn’t hurt anyone.