Definition of billy-o
billy-onoun
billy-o
/ˈbɪli əʊ//ˈbɪli əʊ/Word Originlate 19th cent.: of unknown origin.
namespace
Idioms
like billy-oI ran like billy-o.
(British English, informal)very hard or fast
billy-o
/ˈbɪli əʊ//ˈbɪli əʊ/Word Originlate 19th cent.: of unknown origin.