Green’s Dictionary of Slang

1. to talk nonsense.

1900		E.H. Babbitt ‘College Words and Phrases’ in DN II:i 33: drool, v. To talk indefinitely and aimlessly.
1925		S. Lewis Arrowsmith 236: It’s just that I hope you aren’t going to keep up this drooling.
1943		W.R. Burnett Nobody Lives for Ever 224: Poor old Shake was such a bore, always drooling on about the past.
1977		R. Lloyd Playland 36: I’m not effeminate, I don’t drool, and I don’t hang around schools.
1983		N. Proffitt Gardens of Stone (1985) 211: A couple of old farts sitting around drooling over old times.

2. (orig. Aus.) to waste time, to idle around.

1918		S.S. Clark letter 1 Sept. in Soldier Letters (1919) 161: If we had only gone a little faster, I wouldn’t have minded it, but the column just drooled along.
1923		Wodehouse Inimitable Jeeves 113: I never know [...] whether to drool on and shove in a lot of atmosphere.
1955		N. Pulliam I Travelled a Lonely Land (1957) 232/2: drool – to loaf.