In article valid,
Lazarus Cooke writes
It's an Irish term - although it's now common throughout Britain.

First used by Newland in 'The Erne' 1851. In 1900 William Senior noted
that:

'The baton, or short cudgel, used to perform the last offices for
captured fish is still called the "priest", the name lingering,
perhaps, more in Ireland than in England or Scotland.'
(Pike and Perch)

The implication that the name was dying out was wrong. It is indeed the
standard term throughout the British Isles.

It is a small truncheon used to administer the "Last Rites" to your
trout. just like a priest does.

BTW Wayno has a genuine Welsh priest - I hope he has used it to good
effect.
--
Bill Grey