Desuetude must be closely related to "disuse," right? Wrong. Despite the similarities between them, "desuetude" and "disuse" derive from two different Latin verbs. Desuetude comes from "suescere," a word that means "to accustom" (it also gave us the word custom). "Disuse" descends from "uti," which means "to use" (that Latin word also gave us "use" and "utility"). Of the two, "disuse" is now the more common. "Desuetude" hasn't fallen into desuetude yet, and it was put to good use in the past, as in the 17th-century writings of Scottish Quaker Robert Barclay, who wrote, "The weighty Truths of God were neglected, and, as it were, went into Desuetude."
Examples of desuetude in a Sentence
despite the long years of desuetude, the old manual typewriter seemed to work just fine
Middle English dissuetude, from Latin desuetudo, from desuescere to become unaccustomed, from de- + suescere to become accustomed; akin to Latin sodalis comrade — more at sib