a specious argument for displaying ingenuity in reasoning or for deceiving someone.
2.
any false argument; fallacy.
Origin: 1300–50; < L sophisma sophistry < Gk sóphisma orig., acquired skill, method, deriv. of sophízesthai to act the sophist, become wise; r. earlier sophim, ME < MF sophime < L
[Middle English sophime, sophisme, from Old French sophime, from Latin sophisma, from Greek, from sophizesthai, to be subtle, from sophos, clever, wise.]