From Chanticleer Society

The word is believed to be based on the Hindi word “panch”, which means “five”. As might then be expected it is classically made with the combination of five ingredients: Spirit, Citrus, Sugar, Spice, and Water. While originally it would have been served to groups in a large bowl, over time it eventually worked its way into single serving recipes. In many ways, the more modern Exotic Drinks of the Tiki Bar era were simply single serving punches.

For an example, see: