I heard that the lyrics were inspired by something called "The Miller's Tale". It has to do with the young bride who cheats on her older husband (you can look it up on Wikipedia).
The song lyrics are kinda confused, but the original tale it references didn't make much sense either...
I've been told the name Procol Harum is Latin, but if so the name is misspelled. Procul means "at a distance" or "far from," while harum is the feminine genitive plural of hic, "this," but procul would be used with the ablative, not the genitive. So it could be interpreted as "at a distance from these (women)" but it would be ungrammatical Latin.