Deceptious has the etymological history Archaic formation from Latin dēceptus (past participle of dēcipere 'to deceive') plus -ious. Dēcipere is from de- plus capere ('to take'). The ancestry passes through Latin dēcipere and Latin capere. The prefix de- often marks removal, reversal, or downward motion in Latin formations, helping to explain the word's surface structure. In present use as an adjective, it means "tending to deceive; deceptive (archaic)", keeping the historical formation close to the word's ordinary semantic work. Related words include deception, deceptive, and deceive.