"Tooth and Nail": Idiom Meaning and Origin

"Tooth and nail" means with maximum effort, fierce determination, using all available resources.

Origin

16th century; literal – fighting with teeth (biting) and nails (scratching) as primal weapons when disarmed. First recorded 1562 (John Baret's dictionary).

Usage

• Positive: "She fought tooth and nail for the promotion."
• Negative: "They resisted the reforms tooth and nail."

Conveys intensity, not necessarily physical violence.