From Wiktionary, the free dictionary
From Proto-Finnic *raccahan.
rattsa
- horseback, ahorse, ahorseback
- Hallap, V., Adler, E., Grünberg, S., Leppik, M. (2012) “rattsaa”, in Vadja keele sõnaraamat [A dictionary of the Votic language], 2nd edition, Tallinn