I. ˈāˌpeks noun
( plural apexes -ksə̇z ; or api·ces ˈāpəˌsēz also ˈap-)
Etymology: Latin, summit, small rod at top of flamen's cap; probably akin to Latin aptus fastened, attached — more at apt
1.
a. : the highest or uppermost point : summit , top , peak
the apex of the mountain
as
(1) : the vertex of an angle, a cone, or a pyramid
(2) : the point of the heavens toward which a celestial body is moving at a given time
solar apex
b. : the pointed end : tip
the apex of the tongue
2. : the highest or culminating point : climax , acme , culmination
the apex of his career
the apex of an era
3. : the end, edge, or crest of a vein of mineral nearest the surface
4. in palmistry : a triangle formed by capillary lines on the pads of the fingers and the mounts
5.
a. : the narrow somewhat conical upper part of a lung extending into the root
b. : the lower pointed end of the heart situated in man 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
II. intransitive verb
( -ed/-ing/-es )
of a vein of mineral : to form an apex : present an upper edge