Иногда самые обыкновенные, обыденные даже слова преподносят сюрпризы! Вот, скажем, слово ФОРТОЧКА.
Russian architecture, created as it was for a very cold climate, contains a peculiar invention called the FORTOCHKA. It is a tiny window cut inside a larger pane. Even when windows have been sealed for the long winter, the FORTOCHKA can remain in use, being opened regularly to allow air to circulate.
(from "The Future Is History", 2017)