What is the term for the process of shortening words in language?

The correct answer is the term "abbreviation," which specifically refers to the process of shortening words or phrases. Abbreviations can take many forms, including initialisms (where the first letter of each word is used, such as "FBI" for "Federal Bureau of Investigation") and acronyms (where the initial letters are combined and pronounced as a single word, such as "NASA"). This linguistic practice is common in various languages for reasons such as convenience, brevity, and clarity.

The other options refer to different concepts in language. Combining words generally involves joining two or more words to create a new term, which does not imply any shortening of the original words. Transposition involves changing the order of words or sounds, which is not related to shortening. Condensation might suggest reducing content or ideas but is not a standard term used specifically for the shortening of words. Thus, "abbreviation" is the most precise term for this particular process.