What does the term insertion refer to in linguistics?

Insertion in linguistics specifically refers to the addition of sounds or segments that were not previously present in a word. This phenomenon can occur in various contexts, such as in phonetics, where speakers might intuitively add a sound to facilitate pronunciation or to maintain a certain rhythmic quality. For example, in some dialects, a vowel might be inserted to ease the transition between two consonants, creating a more fluid speech pattern. This helps to illustrate the dynamic nature of language, where sounds can be modified or added for clarity, ease of pronunciation, and fluency.

The other options describe different linguistic processes. The removal of sounds relates to deletion, which is not applicable here. The re-ordering of sounds refers to processes such as metathesis, where sounds within a word are rearranged. Lastly, combining two words into one pertains to compounding, which is distinct from the concept of insertion. Therefore, the focus on the addition of sounds makes this answer clearly the most accurate in defining insertion in linguistics.