tooth and nail

American

adverb

with all one's resources or energy; fiercely.

We fought tooth and nail but lost.

tooth and nail Cultural

To fight “tooth and nail” is to fight with the intensity and ferocity of a wild animal: “The resistance forces fought the invading troops tooth and nail.”

Etymology

Origin of tooth and nail

First recorded in 1525–35

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

ConocoPhillips is the country’s largest nonsovereign creditor and has been fighting tooth and nail to recoup the roughly $12 billion it is still owed.

From The Wall Street Journal • Jan. 19, 2026

Paramount Skydance will be fighting this acquisition tooth and nail, including on antitrust grounds.

From Slate • Dec. 6, 2025

“They will fight tooth and nail over everything.”

From Barron's • Nov. 17, 2025

But according to Ms Skinner's lawyer, all the high-value complex claims are being fought "tooth and nail".

From BBC • Sep. 28, 2025

As with everything else he attempted, he had to fight tooth and nail to win a seat in the stern of one of Al Ulbrickson’s boats.

From "The Boys in the Boat: Nine Americans and Their Epic Quest for Gold at the 1936 Berlin Olympics" by Daniel James Brown

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023