Not kosher, in Jewish law

Usage examples of tref.

And within the hour they were riding alongside the high stockade of Owain’s royal seat and tref of Aber, and the porters and guards at the gates had seen the shimmer of their colours nearing, and cried their coming within.

Within the walls he might move at will, perhaps his freedom extended even to the tref that lay outside the gate.

A half-naked boy in the high summer, Leif could go among the Welsh trefs and the fishing villages here and pass for one of their own, and his talent for acquiring information had brought in beforehand a useful harvest.

Sadly, some previously well-populated districts or can trefs were now uninhabited, either abandoned or destroyed.