Another word for Short form and its Long form of a word

Based on the following example:

Local Area Network (LAN)

You can say that LAN is the short form and the Local Area Network is the long form.

What is the another word for "short form"? (Is 'acronym' a better word for replacing 'short term'? or 'abbreviation' would be a better choice?)

What is the another word for "long form"? (Would 'backronym' a better word choice to replace 'long form'?)

I am open for other word choice to replace 'short form' and 'long form'. Appreciate any help offer.

Update

I have create a table as follows:

|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|    Acronym   |        ???           |      Meaning (?)                                                                                                                                         |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|      LAN     |  Local Area Network  | supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home.              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

What would be the header name to replace the "???"?

And also, would the header name "Meaning" be suitable?

Answer

An acronym is also an abbreviation, and your table would be better headed 'Abbreviation' rather than 'Acronym' because you may have non-acronyms like ADSL.

In fact, if this is a glossary that might contain non-abbreviations like Bandwidth (for example, then 'Terms' is a better heading.

For the second heading you could use 'Meaning', and 'Description' in the third.

Alternatively, merge the second and third columns, or do away with the headings altogether; it's quite clear from the context what's in the table.