1) Cry of respect 2) Mass shout of great respect 3) Old-time greeting 4) Phrase of formal welcome 5) Reverent mass greeting 6) Roman greeting 7) Start of a big greeting 8) Welcoming words 9) Words of acclamation 10) Words of compulsory tribute 11) Words of respect Found on https://www.crosswordclues.com/clue/all-hail
All`-hail' transitive verb To salute; to greet. [ Poet.] « Whiles I stood rapt in the wonder of it, came missives from the king, who all-hailed me 'Thane of Cawdor.' Shak. » Found on http://www.encyclo.co.uk/webster/A/58