A pineapple is a sweet and juicy tropical fruit with tough skin that's typically yellow when it's ripe.
You often hear people say "pineapple on pizza" which can be a pretty divisive topic - some love adding slices of fresh pineapple to their pizza for its sweetness, while others think it doesn't belong. But the word "pineapple" is also used in business and politics, as in the name of a group called the Pineapple Fund that gave away lots of money anonymously. In this sense, the word refers to the idea of being generous or charitable, kind of like the fruit itself - sweet and nourishing.
(chiefly BDSM) A common safeword.
