Here is the example, which is from 'Baker's blue-jay yarn' by Mark Twain. I think the sentence means '(bad words) you might say in everyday life', but I'm not sure.
"He just had strength enough to crawl up onto the comb and lean his back agin the chimbly, and then he collected his impressions and begun to free his mind. I see in a second that what I had mistook for profanity in the mines was only just the rudiments, as you may say."