plimsoll

Meanings

1. A rubber-soled lace-up canvas shoe for sports or onboard ships; a precursor of trainers.
2. The plimsoll symbol ⦵ (or o) that is used as a superscript in the notation of thermodynamics to indicate an arbitrarily chosen non-zero reference point.

1. A surname.

Etymology

From Samuel Plimsoll, a Bristol merchant who created a system of marks and symbols for the waterline of ships. The shoe was possibly named because the line of its sole resembled the Plimsoll line of ship.