This is the insertion of a sound into a word to break up an awkward consonant cluster or to provide a transitional sound between contiguous consonants. In more general usage, blend is used of words like brunch , from breakfast plus lunch , in which pieces of the words are joined but there is no actual overlap. Thus, birdcage and psychohistory are not blends but compounds. And anecdotage in the sense 'anecdotes collectively' is an ordinary derivative of anecdote by means of the suffix -age , often used to form collectives. Blends in our sense are typically deliberate and indeed often skillful creations.
Clipping is an ongoing process in the history of English.
We may distinguish several stages in the process. The most solid state of acceptance of a clipped form comes when many speakers no longer even know what the earlier and longer form of the word was. Thus chap , meaning 'fellow', no longer evokes its antecedent chapman , an old term for a merchant. A hack , meaning a cab, has for most speakers cut its historical ties with hackney , which originally designated a kind of horse. The status of a clipping is more provisional when speakers can in general tell you right off what word it was clipped from.