Green’s Dictionary of Slang

highballer n.

[highball v.]

(US) one who moves fast, works hard etc.

[US]Our Army (US) 13 Dec. 8: Finally, if a soldier-driver wants to inform you that either a policeman or an ambulance will eventually stop a speeder in a fast truck — he’s likely to come out with something like, The ‘Jesse James’ will bag the ‘highballer’ on the ‘red ball’ if the ‘meat wagon’ doesn’t!