(Because I’ve got a summer cold and it’s a day for feeling peevish.)
Another pair for the Homonyms to Watch Out For list: canon and cannon.
Canon, with one n, is the received texts for something, or the authorized meaning of it. (Or a piece of music written in counterpoint, or a member of the clergy.)
Cannon, with two n‘s, is a piece of artillery.
Not the same thing at all.