The antonyms for the word "more abbreviated" are "less shortened," "more elaborate," "more detailed," and "more extensive." These words are used to describe a piece of writing or speech that is longer and more comprehensive than one that has been abbreviated. For instance, if you are writing a report and have to write a condensed version of it, you would use abbreviated terminology. However, if you want to add more details, you would use more elaborate and extensive language.
In conclusion, the opposite of the word "more abbreviated" mainly refers to writing or speech that is longer, more complex, and more detailed compared to the abbreviated version.