Manu was greatly wise and virtuous; he became the progenitor of a race. The offspring of Manu were called Manavas, (human beings.)
धर्मात्मा स मनु/मान् यत्र वंशः प्रतिष्ठितः। मनोर्वंशो मानवानां ततोऽयं प्रथितोऽभवत्॥