Is Warrioress a real word?

Solution 1:

It's in the OED, it has citations back to the 16th century:

1594 R. Carew tr. Tasso Godfrey of Bulloigne iii. 110 Now to the combat had this warriouresse Plighted her selfe.

1596 Spenser Second Pt. Faerie Queene v. vii. sig. S2, Eftsoones that warriouresse with haughty crest Did forth issue, all ready for the fight.

It has also been used (rarely) for the last two centuries, so it's not obsolete. I think it counts as a word.

Solution 2:

By the looks of it, it doesn't seem to be widely recognised as a word. However, Merriam-Webster acknowledges it:

warrioress

a female warrior

(It may be worth pointing out that Internet Explorer's spellchecker underlined "warrioress" as incorrect, suggesting the much more common "warrior".)