defenseless

Lacking any form of defense; vulnerable; open to attack.

• Her look, her attitude, her words were eloquent of the age-old appeal of defenseless woman to her natural protector—man.
• On the port tack layline , you're defenseless against starboard tackers — you have to dip them , no matter how much you may lose doing it — and the wind shadow of boats spinnakering away from the mark can cost you plenty.