The word 极为 is formed through the combination of the adverb 极 (jí), meaning "extremely" or "to the utmost", and the classical Chinese verb 为 (wéi), which here functions as a copula meaning "to be" or "to act as". Together, they create a compound adverb that functions as an intensifier, literally conveying the sense of "is extremely" or "acts as the ultimate degree of". It is used exclusively before adjectives or some psychological verbs (e.g., 重视, 关注) to express a highest degree or intensity, making it a more formal and literary alternative to standalone intensifiers like 很 or 非常.