what is an acronym?

Answer 1

A word formed from the initial letters of a series of words. (eg, IEEE is an acronym for Institute of Electrical and Electronics Engineers).

Answer 2

The above two answers are basically right, but this is one subject on which the dictionaries disagree a bit.

When something's name is multiple words, you might make a shorter version by taking the first letter (or maybe two) from each word (or each main words). Thus you might make
NATO - North Atlantic Treaty Organization
radar - RAdio Detecting And Ranging
FBI - Federal Bureau of Investigation

Notice that sometimes the result is something you can pronounce (NATO, radar) and sometimes the only way you can say it is by naming the letters (FBI is pronounced "ef bee eye").

If you pronounce it, as if it were a word, it's an ACRONYM.
If you can't pronounce it, and must say the initials, its called an INITIALISM.

Where do the dictionaries disagree? Some of them say that an initialism is simply one kind of acronym. http://209.161.33.50/dictionary/radar Most, however, say that to be an "acronym" it must be pronounceable (Oxford English Dictionary, Amer. Heritage Dictionary).

Answer 3

An acronym is a word formed by stringing together the first letters of a name or phrase, to form a new word.
MADD (mothers against drunk driving) is an example.
A couple of words which are acronyms but which have become part of the accepted vocabulary are:
1) laser (Light Amplification by the Stimulated Emission of Radiation) and
2) snafu ( an old military term meaning foul-up. It comes from:
Situation Normal, All (Fouled sic.) Up.

Answer 4

An acronym is a word formed from the initials of words in a phrase, such as NATO ['neyto] from North Atlantic Treaty Organization or "scuba" from "self-contained underwater breathing apparatus." It is often used to include abbreviations but abbreviations are not all pronounceable words. "YDC" is an abbreviation, not an acronym.