[adj] providing light; "the sun's illuminating rays" [adj] highly enlightening; making understandable or clarifying; "an illuminating lecture"; "illuminating pieces of information"
enlightening, light
unenlightening, unilluminating
allegorizing, annotative, autodidactic, brightening, clarifying, coeducational, critical, cultural, demonstrative, demythologizing, didactic, disciplinary, edifying, editorial, educating, educational, educative, elucidative, enlightening, euhemeristic, ex