乘客
chéngkè · HSK 5
passenger
🚌 乘客 = 乘 ride + 客 guest = riding guest = passenger
乘 means to ride or board (a vehicle); 客 means guest or customer. A 乘客 is literally a riding-guest — someone who boards a bus, train, or plane as a paying customer rather than crew.
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.