illuminating

Etymology

illuminate + -ing.

adj

1. Providing illumination or light.
2. (figurative) Providing clarification or explanation; educational, revealing.
   An illuminating article in a recent issue of the Eastern Region's Civil Engineering News points out that where coal is worked over a reasonably large area, it is not only the whole of the strata above the workings, but also an area beyond which is liable to subside at varying rates after the coal has been removed. 1961 November, “Talking of Trains: The subsidence problem”, in Trains Illustrated, page 651

verb

1. present participle and gerund of illuminate.