The roof for the word elucidation is LUC. The origin of its root is Latin and means LIGHT or brightness.
The noun 'elucidation' describes the act of explaining something in order to make it clear to someone else. When you elucidate, you clarify or explain. In other words, you are enghlitening someone.
A root is a part of a word that has meaning. An that meaning could be shifted by affixes, such as prefixes, suffixes, and infixes.