in-deed neither of them ate much and both were more than usually silent.
early 14c., in dede "in fact, in truth," from Old English dæd (see deed). Written as two words till c.1600. As an interjection, 1590s; as an expression of surprise or disgust, 1834. Emphatic form in yes (or no) indeedy attested from 1856, American English.