adj. 25B6; adjective CLEAR, crystal clear, plain, evident, apparent, manifest, patent, conspicuous, pronounced, transparent, palpable, prominent, marked, decided, distinct, noticeable, perceptible, visible, discernible; unmistakable, indisputable, self-evident, incontrovertible, incontestable, undeniable, as plain as a pikestaff, as clear as day, staring someone in the face; overt, open, undisguised, unconcealed, frank, glaring, blatant, written all over someone; informal as plain as the nose on your face, sticking out like a sore thumb, sticking out a mile.
imperceptible.