If you do not use your discretion in keeping words discrete, your lack of discernment may result in indiscretion – and it won’t be discreet.
Let’s be honest: discrete and discreet seem like the sort of word pair that just exist to be a sand trap in the golf course of the language, don’t they? They’re pronounced the same way and they have related meanings. But if you mix up the two, someone is sure to hold it up as evidence of a woeful lack of education. The English language is like a secret society where there’s a new password at every door, and sooner or later you’ll get one of them wrong and be stripped of your disguise and your power – your discretion and your discretion. And those who get it right will mock you indiscreetly. (Come to think of it, it’s more like an elementary-school secret club, isn’t it?)
Let’s start with the difference between the two words. One means ‘separate, distinct’, and it keeps its two e’s separate with the t: discrete. The other means ‘unobtrusive, prudent, secret or good at keeping a secret’, and it keeps both e’s hidden behind the t: discreet. So you see that the spelling suits them to a t and, remembering that, you can spell them with e’s. I mean ease.
But how did these words come to be so similar? Indeed, the noun form of the one is discretion and of the other is discretion. Which is to say there is no way to keep them discrete.
The reason for this is that they were originally the same word. The Latin source is discretus, which comes from the past participle of discernere, which is dis ‘apart’ plus cernere ‘decide, separate’. So if keeping things discrete and keeping things discreet both require discernment, now you know why. The connection between distinction and secrecy comes through prudence: knowing what’s what.
The two words were kidnapped into English in the late 1300s as one word with the two senses already in use. The spelling shifted around for the next couple of centuries as all English spelling did – discreyt, disgret, dyscrete, discreate, discrite, dyscrete, discreete – but it was only in the late 1500s that the spellings became discrete. English users sensed that there were two senses and thought it sensible to keep one for one and the other for the other. And so, almost discreetly – certainly it’s still difficult for many to see the difference – they became discrete.