A bishop is the man in charge of the religious stuff in a large area.
You can usually tell him by his purple shirt (but not always):
Of course bishops are pretty thin on the ground (though not always round the middle) but there are other kinds of bishop which can be found much more easily:
These bishops are everywhere and even come in at least two fashionable colours.
If you can't find a chess set, then you can make your own bishop by getting some wine (usually port) and warming it up with some cloves and slices of orange. Very comforting on a cold night, too.
In Africa there are bishopbirds:
photo by Derek Keats
In Europe there are bishop's mitres:
photo by gbohne
and everywhere there are bishop sleeves, which are full and gathered at the wrist.
If you do see a real live human bishop you could call him My Lord or My Lady...
...except that nowadays he'd probably much rather be called Alan.
Sopt the Frippet: bishop. This word was biscop in Old English, from the Greek episkopos, from epi- which mean on or above or stuff like that, and skopos, which means watcher.