* ἀνδρεία (andreia): This word literally translates to "manliness" or "courage," but it often carries the sense of bravery and fortitude in the face of adversity, particularly in battle. It's probably the closest single word equivalent.
* καρτερία (karteria): This word means "perseverance," "patience," or "endurance." It emphasizes the steadfastness and resilience required to withstand hardship, which are key components of fortitude.
* ὑπομονή (hypomone): Similar to *karteria*, this word means "patience," "endurance," or "perseverance." It highlights the ability to bear suffering without giving up.
The best choice depends on the specific context. If you're looking for the courage to face danger, *andreia* is a good option. If you need a word emphasizing steadfastness and endurance through hardship, *karteria* or *hypomone* would be more appropriate.