The word 'effulgent,' meaning to shine forth brilliantly and radiate powerful light, originates from the Latin 'effulgēre' ('to shine out'). Entered into English in the 18th century, it describes a dazzling, majestic radiance that fills its surroundings, distinct from mere brightness. Synonyms include radiant and luminous, while antonyms are dim and murky. It is often used to describe natural phenomena or profound human qualities.