Definition of "thumb-print" [thumb-print]

• The impression or mark of the inner surface of the terminal joint of the thumb, made upon any receptive surface; especially, the print formed by inking this surface of the thumb and pressing it on paper. Such impressions or prints show the arrangement, of the lines on the surface of the skin, which vary in different persons, and are thus valuable for purposes of identification. See finger-print. (noun)

The Century Dictionary (Public Domain)

• "In some cases, detainees are forced to sign or thumb-print statements under torture or duress without being allowed to read them."
• "Press a small peanut butter cup into the thumb-print—what a taste treat that would be!"
• "The thumb-print of Paradise was on the post-card, and the same print was on the blank sheet of paper that had arrived in the envelope from Scotland Yard."