Forty years or so ago, as I was thumbing through James Boswell’s “Life of Johnson,” I happened upon an obscure word.

Samuel Johnson, the subject of Boswell’s famous biography, and one of the great literary figures of 18th-Century England, put this word in the first English dictionary, which he alone compiled.

On May 15, 1783, Boswell’s biography records Johnson offering this nugget of advice about that old word “cant” to Boswell, and through him to other young writers.

“My dear friend,” says Johnson, “clear your mind of cant. You may talk as other people do. You may say to a man, ‘Sir, I am your most humble servant.’ You are not his most humble servant. You may say, ‘These are sad times; it is a melancholy thing to be reserved to such times.’ You don’t mind the times. You tell a man, ‘I am sorry you had such bad weather the last day of your journey, and were so much wet.’ You don’t care six-pence whether he was wet or dry. You may talk in this manner; it is a mode of talking in Society: but don’t think foolishly.”

If you were to say, gee, “cant” looks exactly like “can’t,” without the apostrophe, you’d be right. As the two words are also pronounced the same, they have been easily confused. Perhaps this is why “cant” so quickly went out of use in spoken English.

See, “cant” doesn’t mean “can’t,” the abbreviation for cannot. In written English, its primary meaning is “the expression, or repetition of conventional, or trite opinions or sentiments.” Especially, the insincere use of pious words.

Cant itself may be out of use, and I would in no way recommend you saying it, lest someone kick you in the seat of your pants for being a pretentious ass, but what it signifies is still relevant.

I think of cant every time I buy something, and the cashier sends me off with “Have a nice day.” I know, we all know, that most of the time, the cashier doesn’t care one nano-bit if we have a nice day, though I’m sure there are many good-hearted ones who do. But convention, and possibly store policy, too often forces insincerity on that cashier.

I know, I know, it is a minor thing, but it bugs me.

So, let me suggest a tidy change. I think the cashier should say instead, “Thank you for your business.” Because the indelible fact is that it is you, the customer, who brings in the money that enables the cashier and other employee(s) to pay his or her bills, to keep a roof overhead, to feed and clothe the kids.

For all of which and more, all employees may be sincerely thankful.

Other well known, and grating, modern examples include — coming especially from politicians — some form of: “Our prayers go out to the families who’ve lost loved ones in this (pick one) terrible tragedy.”

That one is particularly galling when we all know that the very politicians mouthing their condolences for the tragedy have voted repeatedly for the measures that led to it.

Now, this last bit may just my own pique, but I suspect they don’t even mean to pray.

A bit of cant that I’ve amused myself with, and occasionally others, answers the query: “How ya doin’?” And the answer comes back, “not too shabby.”

What the hell does that mean, really? To me the expression has always suggested the existence of a shabby continuum or spectrum, grading the modicum of shabby you claim to possess with, at one end, an overabundance, and at the other, the total lack of it. This implies that the speaker has achieved the golden mean of shabby, possessing just the right amount.

Here’s the question that haunts me in my midnight reveries: What would it mean to have a total lack of shabby?

Trivial or not, as I heard a performer once say during an appearance at Seattle’s Bumbershoot Festival, “some things can really get a hold of your garters.”

Write and let me know what you think.

Robert Whale can be reached at robert.whale@soundpublishing.com.