gladly

The word "gladly" combines "glad," rooted in the Old English concept of brightness and joy, with the adverbial suffix "-ly," which transforms adjectives into manner descriptors. Over time, "glad" shifted from literal brightness (e.g., "glad sky") to metaphorical cheerfulness, and "-ly" standardized its grammatical function as an adverb. The fusion reflects a logical progression from a state of joy to the manner of performing an action joyfully.