dimple

Short definition from Wiktionary

Noun

1. 1
   A small depression or indentation in a surface.
2. 2
   Specifically, a small natural depression on the skin, especially on the face near the corners of the mouth.
3. 3
   A small depression, made with a punch on a metal object, as a guide for further drilling.

Verb

1. 1
   To create a dimple in.
2. 2
   To create a dimple in one's face by smiling.
3. 3
   To form dimples; to sink into depressions or little inequalities.