Green’s Dictionary of Slang

1. an alcoholic drink.

1841

‘Biddy Magee’ Dublin Comic Songster 338: I call’d for a naggin of the old ding dong, / Jist to give polish to the song.

2. (US campus) in pl., side whiskers.

1896

W.C. Gore Student Sl. in Cohen (1997) 13: ding-dongs n. Side whiskers.

3. (US) the head.

1929

in DARE.