- unprotected - lacking protection or defense
Antonyms: protected, secure, bastioned, fortified, battlemented, burglarproof, covert, moated, sheltered, shielded, snug, stormproof, weatherproof
- unguarded, unprotected - lacking protection or a guard; "an unguarded gate"; "his unguarded queen was open to attack"
Antonym: invulnerable (indirect, via vulnerable)