Necessary use of a phrase to circumvent either a vocabulary fault (of speaker or listener) or a lexical gap, either monolingually or in translation.
Unnecessary use of extra words to express an idea, such as a pleonastic phrase (sometimes driven by an attempt at emphatic clarity) or a wordy substitution (the latter driven by euphemistic intent, pedagogic intent, or sometimes loquaciousness alone).
An instance of such usage; a roundabout expression, whether an inadvisable one or a necessary one.
Prattle; foolish speech.