'i

Interjection

1. A friendly, informal, casual greeting said upon someone's arrival.
   • Hi, how are you?

   Synonyms:

   hello, greetings, howdy

2. An exclamation to call attention.
   • I made a speaking trumpet of my hands and commenced to whoop “Ahoy!” and “Hello!” at the top of my lungs. […] The Colonel woke up, and, after asking what in brimstone was the matter, opened his mouth and roared “Hi!” and “Hello!” like the bull of Bashan.1913, Joseph C[rosby] Lincoln, chapter VII, in Mr. Pratt’s Patients, New York, N.Y.; London: D[aniel] Appleton and Company, →OCLC
3. (dated outside of Ireland) Expressing wonder or derision.
   • How did he do that, hi?

See all 5 meanings of hi