The adverb 'vigorously' is built upon the Latin noun vigor, which itself stems from the verb vigere, meaning "to be lively, to thrive." This Latin root is connected to the Proto-Indo-European (PIE) base weg-, meaning "to be strong, lively," a prolific root also seen in words like 'wake' and 'watch.' The suffix -ous was attached to form the adjective 'vigorous,' meaning "full of vigor or energy." Finally, the adverbial suffix -ly was added, a common Germanic construction, to create the modern form describing an action performed with forceful energy and robust health, thus completing the journey from an ancient concept of liveliness to a modern descriptor of intense activity.

Structure: vigor (active strength) + ous (adjective suffix) + ly (adverb suffix) vigor: From Latin vigor (active force, liveliness), from the verb vigere (to be lively, to thrive). Its functional role is the core root noun denoting strength and vitality. ous: A suffix of Latin origin (-osus) via Old French (-ous, -eus), used to form adjectives meaning "full of" or "characterized by" the quality of the root noun. ly: A suffix from Old English -līc (having the form or character of), used to form adverbs from adjectives.