camión
ES [kaˈmjon] · in Mexico, the city bus · same word as Czech kamion (a lorry)
A Mexican colleague told me to take the camión into the centre and I spent a genuine few seconds working out how that was meant to go. In Czech a kamion is a lorry - the forty-tonne sort that queues at the border for hours. I pictured myself climbing up into the cab and asking very politely.
He meant the bus. Nobody had to correct me because I never said any of it out loud. I nodded, walked to the stop and waited, and what pulled up was full of seats.
Spain and Czechia agree on this one. Spanish took camión from French camion, a name for a heavy cart whose own beginnings are murky, and Czech took kamion from that same French word. So in Madrid a camión really is a lorry and a Czech reading is safe. Mexico is where the road forks. The word landed there as motor transport arrived and attached itself to the vehicle that carries people, so the thing rumbling down the avenue collecting passengers became el camión. Freight now has to say so out loud - camión de carga. The word alone will not tell you which one is coming.