What are some words, phrases, and/or aphorisms that, over time, have drastically changed in meaning?

For example, on my question about “decimate”, I used the original meaning (to reduce by one tenth) but nowadays it more likely refers to a circumstance that would reduce whatever to one tenth.

Another example is “Blood is thicker than water” which is generally understood to mean that allegiance is owed to blood relatives above other people, but in fact, derives from the saying “The blood of the covenant is thicker that the water of the womb”. That essentially means that allegiance is owed to those bonded by battle and shared hardship above family.

What are some that you know?