Today the term regular applies to those who observe the dietary rules regarding fiber. In contrast secular applies to those who disregard this rule, and thus are full of sh.....

Hey, why not call your blog "in the [inaudible]?"

That's certainly correct about "secular" vs. "regular" with regard to clergy, but I don't think that that meaning is at the root of our current word "secular". Rather, both uses of "secular" trace back independently to "saeculum", meaning an age or a generation, by way of its adjectival form, "saecularis". "Saecularis" came to mean not just "of an age" but "worldly/non-religious" along the line of thought, I would conjecture, that spiritual matters are eternal, but the worldly comes and goes.

Hmm. I thought I'd just read "regular" as applying to the clergy consisting of parish priests and on up to the pope as distinguished from the monastic types. Maybe I just misread.

Part of the point, which I was too lazy to write about further, is that priests, bishops and the pope were not generally considered monastic during that period. There was tension between the monastic community and the "secular" one.

I don't know that this answers the question, but this entry from the Catholic Encyclopedia distinguishes "clerks regular" from friars and monks.

On the other hand this entry is directly addressed to the term "regular" and says, "The observance of the Rule of St. Benedict procured for the monks at an early period the name of "regulars"." But, it says "Sometimes also the name "regulars" was applied to the canons regular to distinguish them from monks."

So, I think you're right but I also see where my confusion may have come from when I originally saw a reference to regulars.