Is Alexandros a Greek name

Yes , the name is derived from the Greek "Αλέξανδρος" (Aléxandros), meaning "defending men" or "protector of men", a compound of the verb "ἀλέξω" (alexō), "to ward off, to avert, to defend" and the noun "ἀνδρός" (andros), genitive of "ἀνήρ" (anēr), "man". It is an example of the widespread motif of Greek (or Indo-European more generally) names expressing "battle-prowess", in this case the ability to withstand or push back an enemy battle line.