c. 1400, "emulation; act of copying," from Old French imitacion, from Latin imitationem (nominative imitatio) "a copying, imitation," noun of action from past participle stem of imitari "to copy, portray, imitate," from PIE *im-eto-, from root *aim- "to copy." Meaning "an artificial likeness" is from c. 1600. As an adjective, from 1840.
"faculty of the mind which forms and manipulates images," mid-14c., ymaginacion, from Old French imaginacion "concept, mental picture; hallucination," from Latin imaginationem (nominative imaginatio) "imagination, a fancy," noun of action from past participle stem of imaginari "to form an image of, represent"), from imago "an image, a likeness," from stem of imitari "to copy, imitate" (from PIE root *aim- "to copy")
early 15c., "one who imitates or makes a copy of," especially with intent to deceive or defraud, agent noun from counterfeit (v.).
"final or adult stage of an insect," 1797, from Latin imago "an image, a likeness," from stem of imitari "to copy, imitate" (from PIE root *aim- "to copy"). "The name is due to the fact that such an insect, having passed through its larval stages, and having, as it were, cast off its mask or disguise, has become a true representation or image of its species." [Century Dictionary]
"act in imitation of, imitate or copy in speech or action," 1680s, from mimic (n.). Related: Mimicked; mimicking.