Richly comes from Old English rīclīce ('powerfully, mightily'), from rīce ('powerful, wealthy') + -līce ('-ly'), from Proto-Germanic *rīkijaz. The historical chain includes Old English rīclīce and Proto-Germanic *rīkijaz. Older glosses in the chain include "powerfully, mightily", "powerful, wealthy", and "-ly", which help explain the semantic range of the modern word. Morphologically, richly is best read as compound, suffixal formation, and borrowing, yielding an English adverb shaped by both form history and later usage. In current English it functions as an adverb, with the sense "in a costly, abundant, or fully deserved manner". related forms include rich, riches, richness, and enrich. The result is an English adverb whose etymology preserves the older forms while supporting the word's specialized modern meaning.