apothem
noun/ˈæp.ə.θɛm/
Etymology From Ancient Greek ἀπόθεμα (apóthema, “deposit”), from ἀπό (apó, “off, away”) + θέμα (théma, “that which is laid down”).
1
Geometry, Mathematics, Sciences The perpendicular distance from the center of a circle to a chord of the same circle.
2
Geometry, Mathematics, Sciences The distance from the center of a regular polygon perpendicular to one of its sides (a special case of the above).