is ill," rather than "An ill person"; "I am well, but not "I am in a well state of health." Ill in the abstract sense of bad or wicked is obsolescent, or rather practically obsolete except in poetic or local use. Compare illy.
illusion. Compare delusion.
illy: This word should never be used for ill since ill is both an adverb and an adjective. Say, "He behaved ill"; not "he behaved illy." Illy is now obsolescent.
immerge. Compare emerge.
immigrant. Compare emigrant.
imminent. Compare eminent.
immunity and impunity are sometimes confounded. They are both from the Latin, the former being produced by in, not, + munus, service, and the latter by in + pœna, punishment. Freedom from any burden, or exemption from evil, duty or penalty has perhaps not unnaturally, been associated with freedom from punishment. A boy may insult his brother with impunity but can not expect to enjoy a like immunity from strangers.
impending. Compare eminent.
imperative, imperious: Discriminate carefully between these words. That which is imperative may be either mandatory or authoritative; while that which is imperious may be domineering or overbearing.