Etymology
From Latin dēcubō (“to lie in a bed (that is not one’s own)”) + -ation (suffix indicating an action or process or its result). Dēcubō is derived from dē- (“from”) + cubō (“to lie down”), ultimately from Proto-Indo-European *ḱewb-); compare dēcumbō (“to lie down”).
Definitions & examples from Wiktionary (CC BY-SA 3.0).