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.
The substitution of a descriptive word or phrase for a proper name (a type of circumlocution).
Expressing a grammatical meaning (such as a tense) using a syntactic construction rather than morphological marking.
The use of a longer expression instead of a shorter one with a similar meaning, for example "I am going to" instead of "I will".
The use of a proper name as a shorthand to stand for qualities associated with it.