The Collaborative International Dictionary
Deceptive cadence
Deceptive \De*cep"tive\, a. [Cf. F. d['e]ceptif. See Deceive.] Tending to deceive; having power to mislead, or impress with false opinions; as, a deceptive countenance or appearance.
Language altogether deceptive, and hiding the deeper
reality from our eyes.
--Trench.
Deceptive cadence (Mus.), a cadence on the subdominant, or in some foreign key, postponing the final close.
Wiktionary
deceptive cadence
n. (context music English) a falling cadence in which the ear expects the a dominant chord to resolve to the tonic, but resolves to something else (usually a submediant chord) instead.