Synonyms for Defenseless (same or very similar meaning)
WordNet sense 1 (lacking protection or support):
defenceless
WordNet sense 2 (susceptible to attack):
vulnerable
WordNet sense 3 (lacking protection or defense):
unprotected
WordNet sense 4 (without defense):
defenselessly, defencelessly
WordNet sense 5 ((used of persons or the military) not having or using arms):
unarmed
From the ODE community, based on WordNet
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