A word (for example so) that is frequently used in a reflex-like manner in an answer and that has thereby quickly taken on a new, much less specific or much looser meaning or is even almost meaningless and performs a completely new function.
Such a word (or a word that has gone through a similar change) when not used as a reflex-like answer.
Something which is trivial or unimportant.
The quality of being trivial or unimportant.