[pimlottc]

One of my favorites for this is the term “making love”. In older times, this basically meant wooing or courtship - literally trying to and building feelings of love and affection in another person.

Now, of course, it means sex. Which can make can making reading some older texts very surprising for modern readers!

[jerf]

The euphemisms are full of examples like that. Not only can they confuse you in the way you meant, you can just plain miss them. Just yesterday I learned that "watery knees", when used in the context of being very afraid, doesn't necessarily refer to what I thought it referred to, which was just shakey knees that were as stable as water. It refers to pissing oneself, hence, literally, "water" (itself a common historical euphemism for piss) actually on the knees, as well as everywhere else. I don't know how many times I've seen that without putting that together.

(Pardon the bluntness, but explaining one euphemism with another seems rather pointless.)