noun \ˈā-ˌpeks\
plural apex·es or api·ces \ˈā-pə-ˌsēz\

Definition of APEX

: a narrowed or pointed end of an anatomical structure: as a : the narrow somewhat conical upper part of a lung extending into the root b : the lower pointed end of the heart situated in humans opposite the space between the cartilages of the fifth and sixth ribs on the left side c : the extremity of the root of a tooth

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