ANT: Insecure, imperilled, dangerous, Hazardous, exposed.
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KEY: Safeguard.
SYN: Security, protection, [See SABLE].
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KEY: Sagacious.
SYN: Intelligent, discriminating, acute, wise, prudent, foreseeing, shrewd, penetrating, sapient.
ANT: Dull, obtuse, unintelligent, stolid, undiscerning.
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KEY: Sage.