great effect; remarkable efficacy
Rare literary noun; used in formal or classical contexts to describe a powerful or outstanding effect, often of medicine, treatment, or effort.
Ancient documents say this medicine had a great effect on the illness.
Compound of 偉 (great, admirable) and 効 (effect, efficacy). The exact historical derivation is uncertain; it is a Sino-Japanese word (kango) used in classical and literary contexts.