Immediate rephrasing for intensification or justification

Wikipedia Word definitions in Wikipedia
An epanorthosis is a figure of speech that signifies emphatic word replacement. "Thousands, no, millions!" is a stock example. Epanorthosis as immediate and emphatic self-correction often follows a Freudian slip (either accidental or deliberate).

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Epanorthosis \Ep`an*or*tho"sis\, n. [L., fr. Gr. ?; 'epi` + ? to set right again; ? again + ? to set straight.] A figure by which a speaker recalls a word or words, in order to substitute something else stronger or more significant; as, Most brave! ...

WordNet Word definitions in WordNet
n. immediate rephrasing for intensification or justification; "Seems, madam! Nay, it is"

Wiktionary Word definitions in Wiktionary
n. (context rhetoric English) A rhetorical device or element in which a speaker or writer retracts a word that has been spoken and substitutes a stronger or more suitable word; often done for emphasis or sarcasm.