Sthenia

Part of speech: noun

Definitions

1. Unusually great physical or mental energy and vigor in a person ; a state of heightened nervous excitability or tension in the body
2. Abnormal robustness and force of body or mind ; an overexcited, tense condition of the nervous system, the opposite of weakness
3. Extraordinary bodily or mental vigor in an individual ; a condition of marked overstimulation or nervous tension, the reverse of asthenia

Etymology: Sthenia is a back-formation from "asthenia," which means the removal of a word-initial piece that English speakers mistook for a prefix. Asthenia comes from Greek "astheneia," meaning "lack of strength," built from the privative "a-" ("without") and "sthenos" ("strength"). Because "asthenia" looked as if it began with a negating "a-", people reasoned that its opposite should be "sthenia," and the word was created by stripping that supposed prefix away. The result is a term for the opposite condition, excess of strength or vigour, which is used mainly in medicine as a counterpart to asthenia. Its meaning is therefore defined entirely by its relationship to the older word: it names the state of being strong or robust, the reverse of weakness. The new term reverses the logic of the original, turning a prefix-plus-root word into a bare root.

Synonyms: strength, vigor

Antonyms: asthenia