Percolation is the process of a liquid slowly passing through a filter. It's how coffee is usually made.
Percolation comes from the Latin word percolare, which means "to strain through." Percolation happens when liquid is strained through a filter, like when someone makes coffee. Drinking coffee can make you feel perky! Perky comes from the word percolate, too, describing something that bubbles over. Percolation (a noun) is what happens when anything percolates. It’s usually coffee, but chemists use percolation for all kinds of experiments.