gaily

the word 'gaily' is derived from the middle english 'gaili', which itself came from the old norse 'glaðr', meaning bright, cheerful, or glad. the old norse term shares a common proto-germanic ancestor with the old english 'glæd', leading to the modern english 'glad'. the core meaning of 'gay' and thus 'gaily' originally pertained to lightheartedness and mirth. over time, 'gay' underwent a significant semantic shift, but 'gaily' has retained its original sense of cheerful or bright manner, often with a connotation of being carefree or showy, preserving a linguistic snapshot of the word's earlier meaning.

this is a simplex word. it is the adverbial form of the adjective 'gay', with the addition of the english adverbial suffix '-ly'.