相反
xiāngfǎn · HSK 4
opposite
↔️ 相 (mutual) + 反 (reverse) = mutually reversed → opposite
相 means mutual or each-other; 反 means reverse, flip, or oppose. Together: things that mutually reverse one another, i.e. opposites or contraries. Same 反 appears in 反对 (oppose) and 反面 (reverse side).
反 — hand 又 under cliff 厂
Originally a pictograph of a hand (又) turning something over against a cliff or slope (厂), depicting the action of flipping or reversing. From this came the core meaning 'to turn over,' which extended to 'opposite,' 'contrary,' and 'rebel against.' The character is purely semantic, with no phonetic component.