bocardo

Century Dictionary and Cyclopedia

1. n. In logic, the mnemonic name of that mood of the third figure of syllogism in which the major premise is a particular negative, the minor a universal affirmative, and the conclusion a particular negative proposition: as, Some patriarchs (Enoch, Elijah) are not mortal; but all patriarchs are men; hence, some men are not mortal. Of the seven letters which compose the word, five are significant. The three vowels, o, a, o, indicate the quality of the premises and conclusion; b shows that the mood is to be reduced to barbara of the first figure; c, that the reduction is per impossibile. The word was probably invented by Petrus Hispanus. See mood.
2. n. A prison: so called from the old north gate of Oxford, which had this name and was at one time used as a prison.

GNU Webster's 1913

1. n. (Logic) A form of syllogism of which the first and third propositions are particular negatives, and the middle term a universal affirmative.
2. n. engraving A prison; -- originally the name of the old north gate in Oxford, which was used as a prison.