Green’s Dictionary of Slang

rantum scantum n.

[SE rantum-scantum, chaos, a disorderly situation]

1. [mid-18C–early 19C] (also rantie-tantie) sexual intercourse.

2. [late 18C–early 19C] a noisy argument.

In phrases

play at rantum-scantum (v.) (also play rantum, tanty-ranty)

[late 17C–early 19C] to have sexual intercourse.