The compound adjective 'well-nourished' is a transparent combination of Germanic and Latinate elements. The adverb 'well', from Old English wel, signifies a positive or satisfactory manner. The core verb 'nourish' entered English via Old French norir, tracing back to the Latin nutrire, meaning "to suckle, feed, or foster," with its ultimate root in the Proto-Indo-European (s)nau- (to flow, to swim). The '-ed' suffix, of Old English origin, creates a participial adjective, indicating the state of having been nourished. Thus, the word's literal logic is "having been fed in a good manner," which directly corresponds to its modern meaning of being in a healthy state due to adequate nutrition.

Structure: well (in a good manner) + nourish (to feed) + ed (adjective suffix) - well: Old English. An adverb used here to modify the following participle, indicating a positive state or condition. - nourish: Middle English, from Old French, from Latin nutrire (to feed, nourish). The verb root meaning "to feed/sustain". - ed: Old English. A suffix forming past participles, which can function as adjectives describing a state resulting from an action.