inarticulate (adj.)

c. 1600, "not clear or intelligible" (of speech); "not jointed or hinged, not composed of segments connected by joints" (in biology), from Late Latin inarticulatus "not articulate, not distinct," from in- "not" (see in- (1)) + articulatus, past participle of articulare "to separate into joints; to utter distinctly" (see articulation). Of persons, "not able to speak clearly," 1754. Related: Inarticulately; inarticulateness; inarticulable.