adj. 25B6; adjective
a palpable bump : TANGIBLE, touchable, noticeable, detectable.
his reluctance was palpable : PERCEPTIBLE, perceivable, visible, noticeable, discernible, detectable, observable, tangible, unmistakable, transparent, self-evident; obvious, clear, plain (to see), evident, apparent, manifest, staring one in the face, written all over someone.
imperceptible.