Unwary, a.
Etymology: [Cf. Unware.]
1. Not vigilant against danger; not wary or cautious; unguarded; precipitate; heedless; careless.
2. Unexpected; unforeseen; unware. [Obs.] Spenser.
Shades of meaning
Fernald lists unwary only as an antonym, under vigilant.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given