Never or rarely seen 'root' words

You can distract, retract, or subtract, but you can’t just tract.

I find my coworker insufferable, but my boss thinks he’s quite sufferable. In fact, he suffers him gladly.

Captain Joe didn’t make a very good pirate; he was ruthful, feckful and satiable.

I have tant memories of my recent hospitalization.

I’ve recognized people who I hadn’t cognized in years.

I use trammel, kempt and vincible in conversation and correspondence all the time!

Heartened is used far less then disheartened.

A poem my late aunt loved:

In my dotage, I have become
Inept, inert and inane.
O for the days of youth!
To be ept, ert, and ane again.

Both “pease” and “cherries” were originally collective nouns, I believe. The modern singular forms “pea” and “cherry” are back-formations

Didn’t I just say that?

I’ve never heard of “untrammeled”. :o I’m happy to learn a new word today.

Yeah, but I just wanted to specify the “collective” bit; I didn’t think it was clear from what you said. I also wanted to add the “cherries” part.

I looked at the word henchman once and wondered what a hench was. So I looked it up. Hench was from an old German word meaning stallion.

I’m guessing that your henchman was the groom who was strong enough to control the stallion, and he could be called on for other things requiring strength.