Relating to, involving, or characterized by deception; tending to mislead or trick.
From deception (from Latin decipere, 'to deceive') + -al (adjective suffix). This rare adjective form adds grammatical flexibility to discuss deception-related concepts in formal writing.
This word is so rare it barely appears in modern English, but it shows how we can keep making new adjectives from old noun roots—though 'deceptive' does the same job much better!
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