Is an acronym a word?

There is a whiteboard near me with a "Word of the day". Today's word is "G.A.R.P." Does this count as a word? Is an acronym a word?

The answer is sometimes. As Elliott points out in comments, there are many acronyms which have come to be accepted as words. In many cases the original acronym is all but forgotten. (e.g. radar, laser).

But, you can make an argument that upon their acceptance as a word, they cease to function as an acronym. This logic is similar to borrowing a word from another language. These words often change their spelling, capitalization, and usage to fit their new host language.

Most acronyms that become ersatz words are changed to follow typical conventions for capitalization. A good example is the word scuba. This is a word that comes from the acronym SCUBA (Self-Contained Underwater Breathing Apparatus). Note that it is perfectly acceptable to use the all lowercase spelling, and this word can become an adjective now, (e.g. scuba diver).

So, the short answer. Yes, you can treat an acronym like a word. And, if you do it for long enough, it may lose all sense of being an acronym altogether.