acrophony
noun
acroph·o·ny
ə-ˈkrä-fə-nē,
a-
plural -es
1
: the application in the evolution of an alphabet of a pictorial symbol or hieroglyph for the name of an object to the initial sound alone of that name
2
: the naming of a letter by a word whose initial sound is the same as that which the letter represents
Word History
Etymology
acro- + -phony
First Known Use
1878, in the meaning defined at sense 1