noun, plural -ma·ta /-mətə/ Show Spelled[-muh-tuh] Show IPA. Botany. a nut having an outer shell that becomes tough and dry and eventually splits open, as in the walnut and hickory.
Origin:
1855–60; < Neo-Latin < Greek trŷma hole, equivalent to trȳ́(ein) to rub down, wear away + -ma noun suffix marking result