Say you're playing a role-playing game and you end up in one of the other player's dungeons. You could try begging her for clemency — compassion shown by people in power towards people who rebel or break the law.
Clemency is also a weather word, though nowadays it's much more common to hear people talk about "inclement weather" than, say, "the clemency of the storm." Derived from the Latin for "gentle", it came into usage in the 1550s. If you have trouble remembering its meaning, get rid of the "cle" and replace the "n" with an "r". You're left with "mercy", which more or less means the same thing.