perceptible adj.

c. 1300, perceiven, "become aware of, gain knowledge of," especially "to come to know by direct experience," via Anglo-French parceif, Old North French *perceivre (Old French perçoivre) "perceive, notice, see; recognize, understand," from Latin percipere "obtain, gather, seize entirely, take possession of," also, figuratively, "to grasp with the mind, learn, comprehend," literally "to take entirely," from per "thoroughly" (see per) + capere "to grasp, take," from PIE root *kap- "to grasp."

Replaced Old English ongietan. Both the Latin senses were in Old French, though English uses the word almost always in the metaphorical sense. Related: Perceived; perceiving.

early 15c., from Medieval Latin imperceptibilis, from assimilated form of in- "not, opposite of" (see in- (1)) + perceptibilis (see perceptible). Related: Imperceptibly; imperceptibility. OED marks imperceivable (1610s) as "Now rare."

"of or pertaining to the act or power of perceiving," 1650s, from Latin percept-, past-participle stem of percipere (see perceive) + -ive. In reference to intelligence from 1860. From mid-15c. as the name of a type of optical instrument or magic glass revealing future events. The older word in the mental sense was perceptible (q.v.); also compare Middle English perceivaunt "observant" (late 14c.), from Old French and Medieval Latin. Related: Perceptively; perceptiveness.