Ecphoneme

1858, Goold Brown, The Grammar of English Grammars, fourth edition, Samuel S. and William Wood, page 800, The Ecphoneme, or Note of Exclamation, is used to denote а pause with some strong emotion of admiration, joy, grief, or other feeling; and, as a sign of great wonder, it is sometimes, though not very elegantly, repeated […]

The note of exclamation or ecphoneme is used after a word or phrase to express sudden emotion, and is sometimes repeated for emphasis.