What is the meaning of Periphrasis?

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".

Expressing a grammatical meaning (such as a tense) using a syntactic construction rather than morphological marking.

The substitution of a descriptive word or phrase for a proper name (a type of circumlocution).

The use of a proper name as a shorthand to stand for qualities associated with it.

Source: wiktionary.org