'锁孔' (suǒ kǒng) literally combines '锁' (suǒ), meaning 'lock', and '孔' (kǒng), meaning 'hole' or 'aperture'. Together, they form the compound noun 'keyhole' — the small opening in a lock where you insert a key to operate it. This word is concrete and physical, referring specifically to the functional part of a mechanical lock system, not digital or metaphorical 'locks'.

You’ll encounter '锁孔' in everyday contexts involving doors, cabinets, padlocks, or old-fashioned locks. It’s neutral in register — appropriate in both spoken and written Chinese — and commonly appears in descriptive, instructional, or narrative passages about access, security, or repair. Unlike broader terms like '锁' (lock) alone, '锁孔' emphasizes the precise point of interaction between key and mechanism, making it useful for precise technical or observational language.