In English, a garçon is a waiter in a French restaurant — the word has a costume on. A diner in an old film might call “Garçon!” to catch his eye. Though actually, in French the same word is just “boy” or “young man,” and using it to summon a waiter can now sound rude, as if you were snapping your fingers at a servant; modern French service talk prefers monsieur, or simply waiting to be seen. English borrowed the restaurant sense (from the late 1700s) and kept the French flavour, so you meet it on menus, in novels, and in slightly showy speech, not in a typical café in Taipei, where waiter or 服務生 will do.

（法國餐廳的）服務生。法語本義是「男孩」；台灣日常說服務生。