Seldom is a word rarely used, or should I say, is seldom used. It appeared in late Old English through the form of seldan, which meant “infrequently” or “rarely”. The word seldan itself was a borrowing from the Proto-Germanic word selda- which meant “strange” or “rare”, but the etymology of that word remains uncertain. Seldan, when used as comparative, took the form of seldor, and when it was used as a superlative, it became seldost. An alteration of the word seldan was even used by Shakespeare, as he used seld-shown, which meant “rarely exhibited”.