Linguists call it verbal pruning or clipping. The term refers to the tendency of English speakers to shorten words, making them easier to say and to write. Thus, we say ad instead of advertisement and sub instead of submarine sandwich. Bike, bus and even printing (it was once called imprinting) are other examples of words formed by pruning.
Acronyms are another form of pruning, turning phrases into a short series of letters. Sometimes these acronyms, as with NCAA and IRS, become more familiar than the words they represent.
Yet abbreviation is not the only justification for acronyms. We make use them as euphemisms for phrases that may be indelicate or vulgar, such as BS, SOB and BM. And then there are those names and phrases that may say something that's dated or even slightly embarrassing. Some examples:
NAACP It must have been back in the 1960s or 1970s that I heard a black comedian on television (it may have been Nipsey Russell, a favorite of mine) refer to the "National Association for the Advancement of Certain People." Even back then the phrase "colored people" was something to be avoided. If it was racist for whites to use, then perhaps blacks shouldn't be using it either. Yet there it is in the name of the most prominent black organization. Rather than change its name, the group prefers everyone just use the acronym.
KFC A number of years ago, Kentucky Fried Chicken changed its name officially to KFC. The new name, of course, was much easier to say and to fit on signs, but it also served three other functions. 1. It eliminated the word fried at a time when fried foods were looked down upon by nutritionists. 2. It eliminated the word
chicken, thus opening the door for diversifying the chain's menu. 3. It eliminated the word Kentucky, which means something in the United States but not in China and other countries of the world where KFC has been expanding.
A friend recalls a time when she and her husband invited some students from either Africa or Asia to their house for a home-cooked meal. She had to work late that day, however, so on her way home she stopped at KFC and picked up a bucket of chicken, which she placed into her fanciest bowl and served to her guests. The ruse didn't work, however, as one of the students immediately exclaimed, "Oh, the Colonel!"
NCR What company would want to be named after a technologically obsolete piece of equipment? Thus National Cash Register now calls itself NCR Corporation.
YMCA At one time the Young Men's Christian Association and the Young Women's Christian Association were separate organizations usually housed in separate buildings. As this separation began to feel dated, so did the groups' names. They no longer served just young or just Christian people. Nowadays the organizations mostly just call themselves The Y.