One of the books I'm currently reading is The Complete English Poems of George Herbert. Perirrhanterium is the title he gave to one part of his collection of poems called The Temple.

I copied the definition "An instrument for sprinkling holy water, especially upon the newly baptised" verbatim from the notes provided by the editor of the Penguin edition. However, the only references to this word revealed by googling come from sites about Herbert.

Could our ecclesiastical correspondent shed any light on the matter?

Bingley