that can be illuminated or made lighter / understandable

plural of illumination

Something that illuminates.

That illuminates.

(physics) The luminous flux incident on unit area of a surface; measured in lux or lumens.

plural of illuminance

plural of illuminant

One who illuminates; an explainer. / An artist who adds illustrations and decorations to illuminated manuscriptsᵂ.

In an illuminative manner.

(obsolete) bright; clear