Imperceptible

Part of speech: adjective

Definitions

1. So subtle or minute that it cannot be detected by the senses or mind
2. impossible to detect or notice due to being extremely subtle or minute
3. too small or gradual for human senses or awareness to register

Etymology: "Imperceptible" is a straightforward formation: the prefix "im-", meaning "not," attached to "perceptible," which describes something that can be perceived by the senses. "Perceptible" itself comes from the Latin "percipere," meaning "to seize, obtain, or perceive," built from "per-" (thoroughly) and "capere" (to take), so the word's core idea is literally of something that can be grasped by the mind. The word reached English through Middle English, having passed through Middle French and, earlier, Medieval Latin "imperceptibilis." Its earliest roots are in the same Latin verb "capere" that gives English words like "capture" and "receive," so an imperceptible change is, at root, one the mind cannot take hold of.

Synonyms: indiscernible, invisible, unnoticeable, subtle, faint

Antonyms: perceptible, noticeable, obvious, clear, conspicuous