轮胎
lún tāi · HSK 7
tire
🛞 轮 = wheel + 胎 = casing; the rubber casing on a wheel
轮 lún is the same wheel character as in 车轮 car-wheel; 胎 tāi names the rubber casing that wraps it. Wheel-casing = tire.
轮 — car radical 车 + 仑 (phonetic)
轮 is a semantic-phonetic compound. The left side 车 (chē, 'cart/vehicle') gives the meaning, since 轮 originally referred to a wheel. The right side 仑 supplies the sound 'lún'. From 'wheel' it extended to related senses like 'rotate', 'take turns', and 'round'.
胎 — flesh radical 月 (肉) + phonetic 台
A semantic-phonetic compound. The flesh radical 月 (a form of 肉) signals a meaning related to the body, while 台 supplies the sound. Originally referring to the womb or fetus in the womb, 胎 extended to mean embryo, and later by analogy the inner layer of objects like tires.