The Chinese word 深思熟虑 (shēn sī shú lǜ), meaning "to think deeply and consider carefully," is a classical **chéngyǔ** (idiom) formed through parallel and reinforcing semantic pairing. It is composed of two nearly symmetrical verb-phrases: **深思** ("deep thought") and **熟虑** ("ripe/well-practiced consideration"), where 深 (deep) and 熟 (ripe/thorough) are descriptive adjectives intensifying the verbs 思 (to think) and 虑 (to ponder/consider). This structure creates a harmonious rhythm and uses metaphorical adjectives to emphasize a singular, reinforced concept of meticulous and profound deliberation, making the idiom's meaning greater than the sum of its parts.