A craniometric point at the middle of the anterior edge of the chiasmatic groove. ... Origin: G. A small pin, dim. Of tyle, a lump ... (05 Mar 2000) ... 
Type: Term Pronunciation: til′ē-on, -lē-ă; tī′lē-on Definitions: 1. A craniometric point at the middle of the anterior edge of the prechiasmatic sulcus.