A mark conspicuously painted on the port side of all British sea-going merchant vessels, to indicate the limit of submergence allowed by law; so called from Samuel Plimsoll, by whose efforts the act of Parliament to prevent overloading was procured
Plimsolls are canvas shoes with flat rubber soles. People wear plimsolls for sports and leisure activities. a cotton shoe with a flat rubber sole American Equivalent: sneaker (Plimsoll line, probably because of the line around the shoe where the sole meets the top part)