Term for a word used to pad a sentence while the speaker thinks of what to say next [duplicate]
Solution 1:
Although I am making an extrapolated assumption here, rather than quoting from a dictionary or personal knowledge, I would say that such terms are examples of stalling, as exemplified here. If you were to use a noun, then stalling-terms (or stalling terms), stalling words, stallers etc., would all be valid.
However, I have never heard a reference to any such term before (or a descriptive reference such as you gave) so I have no frame of reference to compare to. I think that may end up being a case of neologism.
As well as the wikipedia article itself, this article which comes under the see also section of the wikipedia entry deals with this case tangentally. It uses the words halting and faltering quite a bit, so perhaps rather than using a noun, one might refer to halting, faltering or stumbling (again, in the case of stumbling I'm simply finding like terms from my own knowledge, I can cite no sources) speech patterns or turns of phrase.
Solution 2:
I'm afraid filler is the only word that fits what you need. I'm not sure I understand the "but..." in your question, but the only way I can think of making a similar distinction is that a filler (either a word or just a sound) adds nothing to the sentence, other than to give you some time to think; while you could call "actually," "well..." or "in fact" pet phrases instead. A pet phrase is one that a speaker or writer uses very often even when it's not necessary or there are alternative options that may be better. It does not automatically imply the word or phrase is a filler, but I think with certain contexts it might make that suggestion.
As a more subjective argument, I'd say "Look..." "Listen..." "Well..." "In fact," etc. are like fillers masquerading as rhetoric devices. Or maybe simply both at the same time.**
And as a fun fact, Spanish speakers call these words or sounds muletillas, the diminutive for "crutches," which I think is a much more descriptive term.
**Edit: Actually, I'd ammend this after reading this response: they are still fillers, but phatic is probably more accurate than pet phrase.