discrete and discreet
These are commonly confused but I wondered why. After all, the word discrete should occur at a much lower frequency than the work discreet, given that we are all concerned about being prudent and tactful but rarely bothered by identifying items as discrete. It is rather an academic word for which we would normally use distinct or separate. You would expect the discreet spelling to take over by virtue of its currency, and yet we favour the discrete spelling.
It seems that etymologically these two words are tangled, both deriving from the Latin discernere to distinguish between, with a past participle discretus. In classical Latin discretus meant ‘separate’ and gave rise to a French word which was borrowed into English with various spellings but ended up as discrete. Post-classical Latin made a semantic step with discretus and it came to mean ‘discerning, prudent’. It is from this discretusthat we gained discreet. The idea is that someone who can distinguish clearly between matters is discerning and thoughtful.
The spellings for both words were all over the shop – discreyt, discrite, discreit, discreete, to give just a few. But in the 1600s the confusion settled into discrete in the sense of ‘individual’ and discreet in the sense of ‘tactful’.
If only it had been the other way round! The fly in the ointment is that the Latin ending –etus usually becomes –ete in English, as on complete, delete, replete, etc.
Our instinct therefore is to go for the discrete spelling as falling into line with that pattern. But it is the meaning of discreet that we most commonly have in mind. It is now one of those pairs where we always have to check which one we actually want.