Ĭsm, n.

n. [From the English termination -ism, denoting the theory, doctrine, spirit, or abstract idea of that signified by the word to which it is appended.] A doctrine or theory; especially, used contemptuously or in a bad sense, a fanatical tenet; a specious, but wild or visionary, theory; a plausible and captivating, but unsound doctrine. E. Everett.