coats, periods, and other double meanings

(Lefou, I'm afraid) I've been thinking (a dangerous pastime, I know), and have come to the conclusion that casual English is really very vague. Especially when you get into modern slang. This is largely, in my opinion, because we didn't make up NEW words for slang, oh no, we just used OLD words with a new meaning.

Heck, it took me months to catch up on all the subtly nuanced references to anatomy in conversations at my school.

A few words that can turn a conversation right around if the other guy doesn't know which definition you mean:

Coat. Are we talking paint, or are we talking garment?

Period. Are we talking punctuation, menstrual cycle, or even a passage of time?

Bad apple. Do we need to avoid that creepy guy outside the post office, or is it a warning against a bad culinary experience?

I'm only scratching the surface, I'm sure. There have to be hundreds of words with dangerous double meanings, and while they make English fun...in a way...they also make it incredibly annoying. Just sayin'.

And I'm not even starting down the slippery slope of "that's what she said".

Katie