smooth breathing
- in written Greek, the mark (') placed over an initial vowel to show that in ancient Greek it was pronounced without a preceding (h) sound, or aspirate
- the lack of aspiration thus indicated
See smooth breathing in American Heritage Dictionary 4
noun- The symbol ( ) written over some initial vowels and diphthongs in ancient Greek to indicate that a word does not begin with the sound (h).
- In ancient Greek, an initial vowel or diphthong not preceded by the sound (h).