Sometimes a word that sounds like the right word and feels like the right word isn't actually the right word.
It's an eggcorn.
An eggcorn is a word or phrase that is mistakenly used for another word or phrase because it sounds similar and seems logical or plausible. Take the things that fall from oak trees in the fall. They're acorns, but they sometimes get called eggcorns. And why not? They're kind of egg-shaped, and they are the metaphorical eggs from which new oak trees hatch—hence, eggcorn.
The term was coined by linguist Geoffrey Pullum on the Language Log blog back in 2003, and it's been increasingly used in the years since.
Like crash blossoms, eggcorns are fun to spot in the wild:
And here are some others:
focusing on day-today operations (instead of day-to-day)
happened all over sudden (instead of all of a sudden)
for all intensive purposes (instead of intents and purposes)
If you want to venture down the always-amusing rabbit hole that is the world of eggcorns, visit The Eggcorn Database. Chances are you'll learn that you've been using an eggcorn or two yourself.