god ‧ speed BrE AmE , Godspeed /ˌɡɒdˈspiːd $ ˈɡɑːdspiːd, ˌɡɑːdˈspiːd/ noun [uncountable]
[ Date: 1400-1500 ; Origin: God speed you 'may God give you success' ]
spoken old use used to wish someone good luck, especially before a journey
god ‧ speed BrE AmE , Godspeed /ˌɡɒdˈspiːd $ ˈɡɑːdspiːd, ˌɡɑːdˈspiːd/ noun [uncountable]
[ Date: 1400-1500 ; Origin: God speed you 'may God give you success' ]
spoken old use used to wish someone good luck, especially before a journey
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012