Epexegesis
An added phrase that explains or specifies what was just said.
Epexegesis (Greek, 'additional explanation') is a clarifying addition attached to a preceding word or clause: 'he had one talent — patience', or 'the great question, namely whether the text is genuine'. Grammatically it is often marked by a dash, colon, 'that is', or 'namely'.
It is distinct from apposition, which renames, and from distinctio, which disambiguates a word with more than one sense. Epexegesis narrows or unpacks a term that was accurate but underspecified.
In biblical and classical philology the adjective 'epexegetical' has a technical use — an epexegetical genitive or an epexegetical kai ('and', meaning 'that is') — where the second element defines the first rather than adding a new item. Translators who miss this produce two things where the source has one.
Common mistake: using epexegesis to repeat rather than to specify. If the added phrase teaches the reader nothing new about the term, it is padding.
“...to our God and Father, that is, to him who...”
Keep reading the glossary
Placing a second noun phrase beside a first to rename or specify it.
An explicit definition, mid-argument, of a term the speaker will then rely on — narrowing the sense to prevent ambiguity.
Correcting oneself mid-sentence to arrive at a stronger or truer word.
The use of more words than strictly necessary — sometimes an error, sometimes a deliberate figure of emphasis.