paralogism

UK: /pəˈræləˌdʒɪzəm/ US: (pə ral′ə jiz′əm)

WordReference Random House Unabridged Dictionary of American English © 2025

pa•ral•o•gism  (pə ral′ə jiz′əm), n. [Logic.]

1. Philosophy argument violating principles of valid reasoning.
2. Philosophy a conclusion reached through such argument.

• Greek paralogismós. See para-¹, logo-, -ism
• Late Latin paralogismus
• 1555–65

pa•ral′o•gist, n. 
pa•ral′o•gis′tic, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

paralogism / pəˈræləˌdʒɪzəm/ noun

1. an argument that is unintentionally invalid
   Compare sophism
2. any invalid argument or conclusion

Etymology: 16th Century: via Late Latin from Greek paralogismos, from paralogizesthai to argue fallaciously, from para-¹ + -logizesthai, ultimately from logos word

paˈralogist noun