To do something enthusiastically and successfully. He was hesitant at first, but now that he's been on the job for a month, he's going great guns.See also: going, great, gun
be going great guns
INFORMALIf someone or something is going great guns, they are doing something very well and succeeding. I was going great guns for the first 18 miles or so of the race.Business is going great guns.See also: going, great, gun