Origin: Greek suffix -ism
Initialism has 3 different meanings across 1 category:
a word formed from the initial letters of the several words in the name and pronounced as one word
"`NATO' is an initialism for North Atlantic Treaty Organization"
"the word `scuba' is an acronym for s(elf)-c(ontained) u(nderwater) b(reathing) a(pparatus)"
an abbreviation formed from the initial letters of the several words in the name and pronounced separately
"HTML is an initialism for HyperText Markup Language"
A term formed from the initial letters of several words or parts of words, but which is itself pronounced letter by letter.