|Definition - Pertaining to the tip of the tongue and the sounds made with it, e.g. the [t] in touch.|
Etymology - The word derives from the Latin apex or apicis, a point.
Oxford English Dictionary - Its first citation in this sense is from 1899:
"The part of the tongue which helps to form the narrowing is the front rim. The front rim of the tongue: apical formation."
(Rippmann Elem. Phonet. 71)