I first learned the word "defenestrate" when I was in high school, studying French. My teacher taught us the French word for "window," and then said, "And now you should be able to figure out what the word 'defenestrate' means."
Well, I'd never heard of the word "defenestrate" (it's listed as "rare" usage), but I was able to get a rough idea of the meaning.
You see, the French word for window is "fenêtre," which is awfully close to the main part of the word "defenestrate." (If I'd been studying Latin, I would have had the word "fenestra," which is even closer.)
So now I just needed to figure out what the prefix "de-" and the suffix "-ate" were doing in this word.
"de-" indicates "removal" or "separation" ("deacceleration," for example, means "removal of acceleration").
In chemistry "-ate" indicates a salt formed from an acid: "sulfate," "nitrate," etc. Fortunately, I hadn't yet taken chemistry when this riddle was posed to me, otherwise I might have assumed "defenestrate" means "remove a window by turning it into a salt."
"-ate" also is used to indicate an action ("separate," "agitate," etc.). So maybe it means "the act of removing a window?"
Not quite! It actually means "remove something by throwing it out the window."
It's also used in a more metaphorical sense, to indicate simply that we're getting rid of something quickly and/or dramatically.
Thus, you could form sentences like these:
My students want to defenestrate their text books.
Let's defenestrate all the presidential candidates and start fresh.