Kumara (Sans.) A virgin boy or young celibate. The first Kumaras are the seven sons of Brahma, born out of the limbs of the god in the so-called Ninth Creation. It is stated that the name was given to them owing to their formal refusal to "procreate" their species, and thus they "remained Yogis" according to the legend.
Source: H.P.Blavatsky - The Key to Theosophy, The theosophical glossary