collimate

One might expect a science-y word like collimate to have a straightforward etymology, but that's not the case. Collimate comes from Latin collimāre, a misreading of the Latin word collineāre, meaning "to direct in a straight line." The erroneous collimāre appeared in some editions of the works of ancient Roman statesman Cicero and scholar Aulus Gellius. The error was propagated by later writers—most notably by astronomers, such as Johannes Kepler, who wrote in Latin. And so it was the spelling collimate, rather than collineate, that passed into English in the 19th century as a verb meaning "to make (something, such as light rays) parallel."