The word is delightful, not least because it gives no clue at all to what it means or where it might come from. The recently revised entry for it in the Oxford English Dictionary, which correctly defines it as the paragraph sign, says that it is “now chiefly historic”, which I rather dispute, since it’s easy to find examples in current books on typography and it is still used in standards documents that list character sets.
What makes it truly weird is that experts are sure it’s a much bashed-about transformation of paragraph. This can be traced back to the ancient Greek word paragraphos, a short stroke that marked a break in sense (from para-, beside, plus graphein, write). The changes began with people amending the first r to l (it appeared in Old French in the thirteenth century as pelagraphe and pelagreffe). Then folk etymologists got at it, altering the first part to pill and the second to craft and then to crow. The earliest recorded version was pylcrafte, in 1440; over the next century it settled down to its modern form.
The paragraph symbol, by the way, isn’t a reversed P as you might guess. It’s actually a script C that was crossed by one or two vertical lines. The letter stood for Latin capitulum, chapter.