Lacking any form of defense; vulnerable; open to attack.(adjective)
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Use "defenseless" in a sentence
"Two decades ago, of course, the term "defenseless receiver" hadn't been invented."
"Brazilian President Dilma Rousseff lamented the deaths of what she called "defenseless children" and asked for a minute of silence to honor the youngsters."
"You don’t really understand what the word defenseless means till you see that."