lectus

Lectus, lecti is a second declension masculine, and it is both the bed you sleep in and the couch you eat from - Romans dined lying down, three to a couch, which is where triclinium (three couches) gets its name. A rarer fourth declension lectus, lectus exists for the same object.

The trap is a homograph. Lectus is also the perfect participle of lego, "to read, to gather, to choose", so lectus liber is "a book that has been read", and lecti viri are "chosen men", picked troops. In lecto is nearly always the bed; lectus standing next to a noun it agrees with is nearly always the participle. English gets "litter", the carried bed, through Old French litiere, and the medical "lecture" from the other lego entirely.