a. [ Gr. &unr_; unthinkable; &unr_; priv. + &unr_; perceptible, thinkable. ] 1. Unthinkable. [ Rare ] [ Webster 1913 Suppl. ]

2. (Psychol.) Not subject to conscious attention; having an indefinite, relatively passive, conscious being; characteristic of the “fringe” or “margin” of consciousness. [ 1913 Webster ]

Presentation considered as having an existence relatively independent of thought, may be called sentience, or anoetic consciousness. Thought and sentience are fundamentally distinct mental functions. G. F. Stout. [ Webster 1913 Suppl. ]