Wikipedia
Thenar eminence
The thenar eminence (from the Greek "θέναρ" - thenar, "palm of the hand" and the Latin word "eminentia", meaning projection,) refers to the group of muscles on the palm of the human hand at the base of the thumb. The skin overlying this region is the area stimulated when trying to elicit a palmomental reflex.
Usage examples of "thenar eminence".
Mom was never interested solely in the heart line, head line, and lifelines, but equally in the anatomical snuffbox, the interdigital pads, the heel of the hand, the thenar eminence, and the hypothenar.
Also, there's a couple of lacerations on the left wrist and slight contusions on the thenar eminence, indicating that a bracelet may have been forcibly pulled over her hand.