Not every word has full form. In fact there are thousands of words that does not stand for anything else except their meanings. However, we still have some words that stand only as acronyms for some words. The truth is, you can make a full form of any word as long as you have time for it.
For example, I may see the word 'TAP' means To All Parents, or I can say the word 'CAR' means Commitment, Attention, Reliability. There are so many words with full form but because we have gotten so familiar with them, we tend to think they are real words e.g WHO, World Health Organization and some other words like that. You should also know that, not all acronyms can be used in a formal conversation because most of them are internet slangs and their meanings might be different as you move from one place to another.
Not all words have full forms but there are some words that people are not aware that come with full forms. For example, the newspaper can mean north, east, west, south past and present events report. Cold also means chronic obstructive lung disease. Aim also means ambition in mind which is very fitting because people are always aiming for a certain thing.
Eat can also mean energy and taste. When you eat, you are bringing your body enough energy in order to withstand the various activities that you are planning to do. ETC actually means the end of thinking capacity. This is normally used when there are so many other things that you do not need to mention anymore.
All words could potentially have full forms if you had the tenacity, inclination and creativity to summon up individual words to make a given word stand as an acronym. I think this would inhibit reading if each word read was seen as an acronym, but on the other hand, it might be a wonderful way of spies communicating in letters with secret messages underlying their words.