Stalwart may be archaic in the US but it is in regular use in the UK.

As well as its dictionary use it is a not long-retired British military vehicle

Welcome, madelaine. It's not stalwart that's the antique word, it's stalworth. But do stick around, there's always room for another Brit.

Today's word is a bit disappointing. Why use "stalworth" when you can use the very similar "stalwart". Besides, if you use stalworth some folks may think you ignorant for mispronouncing/misspelling a word, and not give you the chance to justify your usage.

Well, that just goes to show that eyes are selective!

I'd better hide for a bit till everyone forgets that I can't read!

S'okay, madelaine--I can't tell you how many times I've made a post that all too clearly showed that I hadn't read the word of the day. Welcome aBoard!
Di j'all notice that the definition includes: "From Middle English, from Old English staelwierthe"? Still worthy!

An interesting thing about today's word:

Back in the Pittsburgh Steelers' football dynasty of the 1970's, they had a receiver named John Stallworth. Interestingly enough, this definition really fits him!

...and what about Mean Joe Green, then? ;-) (My college roommate was from Pittsburgh.)

ah, you mean Giuseppe Verdi?

Ha!
But no, I'm Jackie. And not usually too mean.