How Kartikeya (कार्त्तिकेय) got his name as “Kartikeya” ?
Daksha Prajapati (दक्ष) has 50 daughters, out of which 10 daughters were married to Dharma (धर्म ), 27 daughters were married to Chandrama (चन्द्रमा) and 13 daughters were married to Rishi Kashyap (कश्यप)
All daughters who were married to Chandrama (चन्द्रमा) are referred as 27 Nakshatra (नक्षत्र ). As per Hindu astrology, Kṛttika (कृत्तिका) is the third of the 27 Nakshatra .
The six Krittikas (कृत्तिका) who raised the Hindu God Kartikeya are Siva, Sambhuti, Priti, Sannati, Anasuya and Kṣama.
कृत्तिकाभ्युपपत्तेश्च कार्तिकेय इति स्मृतः – Mahabharata, Adi Parva 66.24
Since Kumara accepted six Krittikas as his mothers, therefore he is referred as Kartikeya (कार्त्तिकेय)