【Illuminate】 , 【illumine】 ,  【light】 ,  【lighten】 ,  【enlighten】 ,  【illustrate】  are comparable when meaning to fill with 【light】 or to throw 【light】 upon.

【Illuminate】 implies the use of a bright 【light】 or of something comparable to it in such a way that what is dark is made bright or what is complicated, obscure, or vague is made clear.

【Illumine】  is chiefly literary or poetical for  【illuminate】 .  【Light】 ,  【lighten】 , and  【enlighten】  carry a stronger implication of providing with 【light】 for clear seeing than of throwing a 【light】 upon.

【Light】 is the most consistently literal of these terms, though it often carries a suggestion of brightening the way of one who otherwise might stumble or go astray.

【Lighten】 , like  【light】 , basically implies a making brighter or a lessening of darkness, but it has more extended and poetic use.

【Enlighten】 , which has almost wholly lost its basic meaning of to make physically 【light】 or bright, is common when filling with intellectual or spiritual 【light】 is implied.

Sometimes the term implies that one has been supplied with information necessary to the understanding of something and sometimes it implies sufficient education and experience to enable one to meet all needs and, especially in the adjective enlightened, to remove or overcome superstition, prejudice, or intolerance.

【Illustrate】  (see also EXEMPLIFY ) is somewhat rare in a sense which approaches that of  【illuminate】 and in which it suggests the shedding of luster rather than of 【light】 , embellishment rather than elucidation, and distinct exhibition rather than a bringing into view.