F is for . . .
One cold winter day, my then 5- or 6-year -old brother said exactly the following:
"It's the F-word cold!"
"Trevor!" my mother exclaimed. (Even if you're not saying the actual F-word, you really shouldn't even be referring to it, at that age.)
"What?" he innocently replied.
"We don't say that word."
"Is that what you meant by 'the F-word'?"
"Yeah. It's freezing cold!"
"Oh. Just say 'freezing,' honey."
(One suspects that he had heard the phrase "the F-word" somewhere, and had wrongly surmised that it could stand in for any F-word.)