Unwary

Part of speech: adjective

Definitions

1. Not cautious or alert to possible dangers or difficulties
2. Lacking vigilance or caution to potential risks or threats
3. Demonstrating a careless attitude towards possible hazards or challenges

Etymology: "Unwary" is a plain formation: the negative prefix "un-" attached to "wary," which itself goes back to the Old English "wær," meaning cautious or watchful. The English adjective is built directly from those two parts, so its sense follows from them: someone who is not on guard against what might go wrong. The word has a long native pedigree. Old English already had "unwær," meaning both unaware and unwary, and a fuller form "unwærlīċ," meaning heedless or careless. Modern "unwary" thus continues a pattern English speakers have used for over a thousand years, pairing a negated form of "wær" with a sense of carelessness toward danger.

Synonyms: careless, heedless, inattentive

Antonyms: cautious, wary, vigilant