可乘之机
kěshèngzhījī · HSK 7
Can
🐎🚪 可乘之机 = can + ride + of + chance: an opening you can ride, an opportunity ripe to exploit
Break it down: 可 can, 乘 ride or take advantage of, 之 of, 机 opportunity. So it names a gap or weak spot a rival can mount and exploit, like an unguarded door left open.
可 — mouth 口 + breath marker 丁 (modified)
可 originally depicted a mouth (口) with a curved stroke suggesting exhaled breath or speech, conveying approval or assent. From this came the meaning 'to permit' or 'can,' as granting permission was expressed verbally. Today it broadly means 'may,' 'can,' or 'approve.'
乘 — person 人 atop tree 木 with two feet
Originally a pictograph showing a person standing on a tree, depicting climbing or mounting. The meaning extended from 'to mount/climb' to 'to ride' (a vehicle or animal), and later to 'multiply' in mathematics. The reading shèng (fourth tone) preserves the older sense of a chariot or vehicle.
之 — foot 止 above ground line 一
Originally a pictograph of a foot (止) stepping forward from a baseline, meaning 'to go' or 'to proceed'. Over time the concrete 'going' sense faded, and 之 was borrowed as a grammatical particle marking possession ('of') or as a pronoun ('it'), which became its dominant use in Classical Chinese.