heart of oak

A trait said to belong to a very emotionally and/or mentally strong person. I don't know how a soldier does it—he or she must have a heart of oak. My brother has a heart of oak and has remained totally calm while coping with his wife's sudden illness.

Common Names:

Name	Pronounced	Usage
Maighread	-	Scottish
Fridtjof	FRIT-shof (Swedish), FRIT-yof (Swedish)	Swedish, Norwegian, Danish
Vaishnavi	-	Hinduism, Tamil, Indian, Telugu, Marathi
Albertina	ahl-ber-TEE-nah (Italian, German)	Italian, German, Dutch, Portuguese
Kjellfrid	-	Norwegian
Denholm	-	English (Rare)