A carnser (or caurnser) is a causeway or raised bank or embankment.
The term is from East Anglian English which arose in Norfolk and Suffolk.
[1] In Ipswich, Suffolk it has been used to describe remnants of the town's earthen ramparts, which provided a raised area on which houses were built.
Elsewhere the term was applied to a raised walkway whereby pedestrians could avoid walking in water flowing in the street, as in Stoke Street.
The historic use with the variant use of "Caunsey" has been found dating back to 1564.