on the wagon prepositional phrase2 •Abstaining from drinking any alcoholic drink, usually in the sense of having given it up (as opposed to never having partaken); teetotal.I wanted to git him some whisky, but he shuck his head. 'I'm on the water-cart,' sez he. — 1901 •Maintaining a program of self-improvement or abstinence from some other undesirable habit.He’s been on the smoking cessation wagon for two weeks now.
