What does Alexander mean?
From Greek 'alexein' (to defend, protect) and 'aner/andros' (man), so 'defender/protector of men'. Note this is strictly 'defender' rather than 'warrior', though its martial fame comes from Alexander the Great.
What does Nicholas mean?
Nicholas comes from the Greek for “victory of the people.” St Nicholas, a 4th-century bishop famed for secret gift-giving, became the model for Santa Claus.