lustily

The adverb 'lustily' is built upon the now-archaic adjective 'lusty', which in Middle English meant pleasant, delightful, or full of healthy vigor, stemming from the Old English concept of 'lust' as pleasure or desire. Over centuries, the core semantic link shifted from general pleasure and eagerness to specifically denote robust physical energy and hearty enthusiasm. The addition of the adverbial suffix '-ly' directly transforms this quality of vigor into a manner of action, resulting in the modern senses of doing something with great strength or in a loudly vigorous way.

Structure: lusti (healthy, vigorous) + ly (adverb suffix) - 'lusti': From Middle English 'lusti', from Old English 'lustfull' (pleasing, desirable), related to 'lust' (pleasure, desire). Its functional role is the adjectival base meaning "full of vigor or health." - 'ly': A productive English suffix forming adverbs from adjectives, from Old English '-līce'.