较劲
jiào jìn · HSK 7
to match one's strength with
🤼💪 较 = compare + 劲 = strength: compare strength, so dig in and compete head-to-head
较劲 stacks 较 (compare) onto 劲 (strength/force): two people measuring their force against each other. It covers literal contests and the stubborn refusal to back down when you set yourself against someone.
较 — car radical 车 + 交 (jiāo, phonetic)
较 is a phono-semantic compound: 车 'cart/vehicle' gives the meaning, while 交 supplies the sound. It originally referred to the crossbar on a chariot, then extended by comparison of parts to mean 'compare' or 'relatively', its main modern senses.