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 the primary sense of Modern French percevoir is literal, "to receive, collect" (rents, taxes, etc.), while 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.