You searched for: “acrophonetic
acrophonetic (adjective), more acrophonetic, most acrophonetic
Pertaining to a word in which the name of it refers to an alphabetical symbol representing the initial sound of that word; acrophonic: Patty had a book that was full of acrophonetic terms, as "apron" to stand for "a" which is also pronounced like the first letter of the alphabet.

Another acrophonetic term is "bravo" which represents the letter "b".