* Appearance: Words like *deas* (nice, pretty), *álainn* (beautiful), or *maith* (good) could be used, but they don't specifically mean "handsome." The best choice would depend on whether the person is a man or woman, and the specific features contributing to their handsomeness.
* Attractiveness: *Tarraingteach* (attractive) might be suitable, although it's more general than "handsome."
* Manly: If the handsomeness is linked to a masculine appeal, words like *firinscneach* (manly) or *fiorlaoch* (heroic) could be considered, but again, these aren't direct equivalents.
Therefore, there's no single perfect translation. You'd need to choose the word that best fits the context and your intended meaning.