c. 1400, "spiritual, incorporeal, not consisting of matter," from Medieval Latin immaterialis "not consisting of matter, spiritual," from assimilated form of in- "not, opposite of" (see in- (1)) + Late Latin materialis "of or belonging to matter" (see material (adj.)). Sense of "unimportant, of no consequence" is first recorded 1690s from material (adj.) in its meaning "important" (16c.). Related: Immaterially (late 14c.); immateriality.
