Ostmark and tattletale gray. Creese, cranch, and cramoisie. Probang and prolan. Octandrious. Complement-fixation test. What do these words have in common? They have recently been removed from dictionaries.

Every few months, the public goes wild at the news that certain words (crowdsourcing, OMG, man cave) have been added to our venerable reference books. Meanwhile, other words get taken out—though generally with less fanfare. Merriam-Webster doesn’t want its Collegiate version to grow too large or unwieldy; and so, the Merriam-Webster lexicographer Kory Stamper told me, “we do have to drop entries every time we produce a new edition.”

To determine which words are most relevant today, editors comb through a variety of sources (Google Books, LexisNexis, other dictionaries, the entire Internet). A word that’s still widely read—a thee or a thou—should stay, even if it’s not used by contemporary English speakers. To survive in the Collegiate Dictionary, Stamper says, a defunct word must appear in books that the average high-school or college student is aware of. So an archaic word found in Shakespeare or Milton gets a reprieve, but one favored by Samuel Pepys or Anthony Trollope may not.

Frequent targets for deletion include abbreviations, biographical entries, and geographical names, as well as scientific and medical terms, which are regularly rendered obsolete by new phraseologies. Goodbye, Vitamin K. Hello, riboflavin. “The kinds of entries we’ve removed include ’70s slang—like Panama Red, a type of marijuana—and obsolescent technology terms like cassette memory,” says Steve Kleinedler, the executive editor of The American Heritage Dictionary. Complicating matters, usage can be fickle. In the late 1990s, lexicographers considered chad a serious candidate for deletion—but then came the 2000 presidential election. Which words now hang, chad-like, in the balance? Eath (“easy”) has not been widely used since the 19th century, says Stamper. Poor old landlubberliness (“the state of being like a landlubber”) doesn’t get much love, either.