In these ongoing columns about oddball vocabulary, I try to provide not only definitions, but also etymology (that is, the word’s origin) — if it’s sufficiently clear and interesting. (Granted, that last adjective can be a stretch with etymology.)

But last week, I somehow skipped the origin of peduncle, a stalk-like structure found in many plants and animals. Inexplicably, your intrepid linguist managed to miss its obvious relation to the well-known Latin base ped-, meaning “foot.”

This week, I thought I’d go a step farther (if you’ll forgive the pun) and use this single word as a springboard for assorted linguistic trivia.

So in the words of Morpheus from The Matrix, let’s see how deep the rabbit-hole goes:

Along with its connection to “foot” (in the sense of support from below), peduncle also ends with a “diminutive suffix” — that is, a short added unit meaning “small” or “smaller.” Examples include: -ette, as in kitchenette, novelette and cigarette (literally, “little cigar”); and -c(u)le, as in article, molecule and corpuscle.

The two-syllable suffix in peduncle is not terribly common, though it does occur in carbuncle and homunculus (the latter meaning fetus, dwarf or small human). Initially I thought, “That can’t be related to our word uncle!” But in fact, the indispensable Online Etymology Dictionary shows that this relative term originally meant “little grandfather.” That’s also where we get avuncular, meaning “kind, patient or generous, especially toward youth” — yes, like an uncle!

(Here might be a good place to acknowledge this column’s considerable debt to both the OED and Dictionary.com.)

As for ped-: I’m sure you can think of many common foot-words from that one — for instance, pedestrian, pedometer and pedal (operated with a foot; there’s also a small pedal-driven boat called a pedalo).

Likewise, let’s not forget centipede and millipede — where the base combines, respectively, with Latin roots meaning “hundred” and “thousand” — along with biped, quadruped and of course pedicure.

That last term has also produced the terrific new word mani-pedi — for the whole works, with mani- yet another Latin base meaning “hand,” of course; you won’t find mani-pedi in many dictionaries just yet — but Merriam-Webster has it, and that’s good enough for me.

A few other words from ped- are perhaps not so obvious: expedition (originally, a trip on foot) and its base expedite, meaning to move along faster (again, originally on foot). Also: impede (originally, to get in the way of one’s feet) and pedestal — literally “foot-stall,” as in a small place to sit down or put things.

Incidentally, it might be worth mentioning a completely different Latin base which is spelled the same but means “child” — as in pediatrician, pedophile and even encyclopedia (in the sense of educating youth).

Going even deeper down the rabbit-hole, we find Greek getting into the mix — which often happens, since there was so much cultural interchange between the empires of ancient Greece and Latin-speaking Rome. The Greek version of ped- is pod-, giving us tripod, podiatrist, sauropod and podium, the latter being a place where one stands … on one’s feet, of course.

The rarer antipodes is defined as “places diametrically opposite each other on the globe” — like the North and South poles, for example. It originally meant “opposite feet.”

There’s also an animal-kingdom order called octopods, which includes not only those famous eight-legged ocean-dwellers, but also the argonaut or paper nautilus — which is technically an octopus, though it makes and carries a shell for its eggs.

And we get platypus from this, too; with its webbed appendages, this creature has a name that literally means “flat feet.”

But … how did the D in ped- and pod- turn into an S in octopus and platypus?

Well, here’s another fascinating linguistic phenomenon: Those two sounds are made fairly close to each other in the mouth — with your tongue behind your teeth. (You can grasp this quickly if you first make a “duh” sound and then the hissing noise of an S.)

This in turn explains how words like include and provide wind up with an S when you add a suffix: inclusion, provision, etc. Needless to say, there are many other examples (video, vision); and in fact, this sort of respelling due to pronunciation happens really often in English.

Just try adding the “not” prefix in- to the word possible, you’ll see how the N swiftly changes to an M; a similar change happens when you add in- to words like legible and resistible.

Sigh. That’s a whole different rabbit-hole — one for another column, I suppose; for now, let’s pull out of this wordy wonderland, and I’ll see you here again soon.

I wouldn’t want to make you late….