Meaning

noun a garden plant of the genus Antirrhinum having showy white or yellow or crimson flowers resembling the face of a dragon

origin(1570s) From snap + dragon, from a fancied resemblance, especially by playing children that the flower is a dragon that opens its "mouth" when squeezed on the sides. Compare for this sense the etymology of Dutch leeuwenbek (“snapdragon”, literally “lion's mouth”) and German Löwenmaul. An ancient name was Old English hundeshéafod (literally “dog's head”). For the parlour game sense, the 1704 Swift…

Etymology from Wiktionary, CC BY-SA 3.0