Smooth breathing
diacritical marks used in polytonic Greek, Coptic, and old Cyrillic orthographies, as well as in Ugaritic or Egyptological transliteration

The smooth breathing (Greek: ψιλή psilí) is a diacritical mark used in the polytonic orthography of Greek. In Ancient Greek, it marks the absence of the voiceless glottal fricative /h/ from the beginning of a word.
Some authorities have interpreted it as representing a glottal stop, but a final vowel at the end of a word is regularly elided (removed) when the following word starts with a vowel and elision would not happen if the second word began with a glottal stop (or any other form of stop consonant). In his Vox Graeca, W. Sidney Allen accordingly regards the glottal stop interpretation as "highly improbable".
The smooth breathing mark ( ᾿ ) is written as on top of one initial vowel, on top of the second vowel of a diphthong or to the left of a capital and also, in certain editions, on the first of a pair of rhos. It did not occur on an initial upsilon, which always has rough breathing (thus the early name ὕ hy, rather than ὔ y) except in certain pre-Koine dialects which had lost aspiration much earlier.
The smooth breathing was kept in the traditional polytonic orthography even after the /h/ sound had disappeared from the language in Hellenistic times. It has been dropped in the modern monotonic orthography.
History
The origin of the sign is thought to be the right-hand half ( ┤ ) of the letter H, which was used in some archaic Greek alphabets as [h] while in others it was used for the vowel eta. It was developed by Aristophanes of Byzantium to help readers discern between similar words.
“Smooth breathing” enters the record as diacritical marks used in polytonic Greek, Coptic, and old Cyrillic orthographies, as well as in Ugaritic or Egyptological transliteration. Crown Archives preserves that source wording while asking what Smooth, breathing and diacritical can confirm, complicate or overturn.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jun 19, 2026. The linked authority identifier is Q514198. None of the 0 selected statements returned an explicit reference.
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This entry incorporates text from “Smooth breathing” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.