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
Bethania	-	Spanish, Biblical Latin, Biblical Greek
Szczepan	SHCHE-pahn	Polish
Obi	-	Western African, Igbo
A&Eth;Alsteinn	-	Icelandic, Ancient Scandinavian
Bryony	BRIE-ə-nee	English (Rare)
Marlene	mahr-LE-nə (German), MAHR-leen (English)	German, English