Definitions:

1. Name of a fly that bites or annoys livestock, particularly cattle, causing them to move about restlessly. NOUN
   • The gadfly's sharp sting left a painful reminder on the cow's back.
2. Refers to a person who persistently annoys or criticizes others, especially in order to provoke them into action or change. NOUN
   • The gadfly's presence in the room became an unwelcomed distraction for the meeting attendees.
3. Used to describe someone who challenges the status quo or conventional thinking, often by asking difficult questions or pointing out flaws in existing systems or beliefs. NOUN
   • The gadfly's constant questions eroded the politician's carefully crafted image.

Synonyms:

• agitator
• annoyance
• annoyer
• botherment
• gnawer
• nuisance
• pest