h₂ner-
“man, vital force”man, hero, strength
Root for man/vital force, yielding Greek aner/andros (man), Latin Nero.
Discussion
The PIE root *h₂ner- (man, vital force, masculine energy) is the base from which the Greek anḗr (man) and its oblique stem andr- derive — giving English android, androgyny, Alexander ("defender of men"), and the combining form andro- in scientific vocabulary. The full treatment of this root's reflexes across Greek, Sanskrit (nár-, "man, hero"), and other branches appears at the main *h₂ner- entry. This root represents one of several PIE words for "man": *h₂ner- emphasised vital energy, *wih₁rós emphasised social standing (giving Latin vir → virile, virtue), and *dʰǵʰm̥on- emphasised earth-origin (giving Latin homō → human). The PIE speakers distinguished at least three concepts where modern English uses the single word "man."
Notes
Pokorny 765. English Andrew (manly), anthropology (via Greek folk etymology).