Source : Webster's Revised Unabridged Dictionary (1913)

All hail \All` hail"\ [All + hail, interj.]
   All health; -- a phrase of salutation or welcome.

Hail \Hail\, interj. [See {Hail}, v. t.]
   An exclamation of respectful or reverent salutation, or,
   occasionally, of familiar greeting. ``Hail, brave friend.''
   --Shak.

   {All hail}. See in the Vocabulary.

   {Hail Mary}, a form of prayer made use of in the Roman
      Catholic Church in invocation of the Virgin. See {Ave
      Maria}.