Green’s Dictionary of Slang

1. an argument, a dispute.

1833

Huntingdon, Bedford & Peterboro Gaz. 10 Aug. 2/2: If the former [motion] be not previously withdrawn, we may expect [...] a regular rumtitum will take place.

2. enthusiastic, if ultimately empty talk.

1908

Bulletin (Sydney) 16 July 18/1: To be serious: What’s the sum / Total of this rum-ti-tum, / All this bounding ’Murkan slang / Gospel with a Yankee twang? / Does the soul the faster trudge / Hustled by such foolish ‘fudge,’ / Prodded in her mystic home / By the fussy quacks who roam.