rough breathing

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An aspirate sound in ancient Greek like that of the sound (h) in English.
• noun The symbol ( ʽ ) written over some initial vowels and the letter rho in ancient Greek to indicate that a word begins with the sound (h).
• noun In ancient Greek, a word beginning with the sound (h) plus a vowel or diphthong.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The sound equivalent to an initial "h" before a vowel or an "r" in Ancient Greek.
• noun The mark used to indicate the occurrence of the sound.