According to a documentary on Procol Harem on the TV ages ago. Procul Harem - with a u in there instead - is Latin for: Beyond these things. However the 5th member of the band who didn't appear on stage, but did the lyrics (I've forgotten his name) - He had a cat called Procol Harem - with an o instead. Procol Harem - So - There you go..
Its worth checking out Robin Trower, if you haven't already - after he left Procol harem, he went on to be one of the greatest guitarists to emerge from the 70s.