1) Start 
Thelarche iː is the onset of secondary (postnatal) breast development, usually occurring at the beginning of puberty in girls. Its etymology is from Greek θηλή [tʰelḗ], `nipple” and ἀρχή [arkʰḗ], `beginning, onset”. Thelarche is usually noticed as a firm, tender lump directly under the centre of the nipple (papilla and areo...
The beginning of development of the breasts in the female. ... Origin: thel-+ G. Arche, beginning ... (05 Mar 2000) ... 
(the-lahr´ke) beginning of development of the breast at puberty.
Type: Term Pronunciation: thē-lar′kē Definitions: 1. The beginning of development of the breasts in the female.
Thelarche: The beginnings of breast development at puberty. Thelarche is now a normal event at an earlier age (e.g., age 8) than in the past. The term thelarche comes from two Greek words: 'thele,' nipple + 'arche,' beginning. Thelarche is frequently (and incorrectly) written without the 'h' as telarche.
[n] - the start of breast development in a woman at the beginning of puberty
noun the start of breast development in a woman at the beginning of puberty