Merriam-Webster Collegiate Dictionary - lineament

 noun  Etymology: Middle English, from Latin ~um, from lineare to draw a line, from linea  Date: 15th century  1.  a. an outline, feature, or contour of a body or figure and especially of a face — usually used in plural  b. a linear topographic feature (as of the earth) that reveals a characteristic (as a fault or the subsurface structure)  2. a distinguishing or characteristic feature — usually used in plural  • ~al adjective