These meaning is taken from Adi Shankaracharya commentary of Brihadaranyaka Upanishad 1.3.1
- स्वेषु एव असुषु रमणात् सुरेभ्य:
The one who indulge in one’s own असु (vital senses) is called Asura
- यस्मात् दृष्टप्रयोजनज्ञानकर्मभाविता असुरा:
The one who is guided by what is seen and what is concluded.
गता: असव: येषां ते – गतासव: ( बहुव्रीहि )