Pronunciation: (lin'ē-u-munt),[key] —n. 1. Often, lineaments. a feature or detail of a face, body, or figure, considered with respect to its outline or contour: His fine lineaments made him the very image of his father. 2. Usually, lineaments. distinguishing features; distinctive characteristics: the lineaments of sincere repentance. 3. Geol.a linear topographic feature of regional extent that is believed to reflect underlying crustal structure.