apex

noun (plural apexes or apices /ˈeɪpɪsiːz/)

• 1the top or highest part of something, especially one forming a point:the apex of the roof figurativethe central bank is at the apex of the financial system
• Geometry the highest point in a plane or solid figure, relative to a base line or plane.
• Botany the growing point of a shoot.

• 2the highest point of achievement; a climax:the apex of his career was in 1966 when he hoisted aloft the World Cup for England

• 3 Motor Racing the point in turning a corner when the vehicle is closest to the edge of the track.

verb

• 1 [no object] reach a high point or climax: melodic lines build up to the chorus and it apexes at the solo

• 2 [with object] Motor Racing turn (a corner) very close to the edge of the track: he understands when to apex a corner