Keshava is another name for Krishna and appears as the 23rd and 648th names in the Vishnu sahasranama. Kesava' (Sanskrit) is the first of the 24 epithets of Lord Krishna

• According to Adi Sankara' s commentary on the Vishnu sahasranama, Keshava has three meanings:

The name means "One whose Kesa or locks are beautiful." Alternatively, it means one who is Himself the three: kah Brahma; ah Vishnu and Isa Shiva. In still another meaning, Keshava means one who destroyed the asura or demon Kesi in the Krishna avatar. It also means One who is endowed with the rays of light spreading within the orbit of the sun. Still furthermore, it means One who is endowed with divine powers of Brahma, Vishnu and Siva.

Cited from reference: Sri Vishnu Sahasranama, commentary by Sri Sankaracharya, trasnlated by Swami Tapasyananda, available at Sri Ramakrishna Math, Chennai. available at India web site: http://www.sriramakrishnamath.org and US site: http://www.vedanta.com.

For more information, see the wikpedia article on Krishna.