分裂
ぶんれつ · bunretsu · JLPT N1 · noun
split
分 — knife 刀 + eight 八 (split apart)
分 originally depicted a knife (刀) cutting something into two parts, shown by 八 above (which itself meant 'divide'). The core sense is 'to divide' or 'split', from which extended meanings like 'portion', 'minute', and 'part' developed. Pronounced fèn, it carries the sense of an allotted share.
裂 — 列 (liè, phonetic) + 衣 (clothing)
A semantic-phonetic compound: 衣 'clothing' gives the meaning and 列 supplies the sound. The original sense was tearing or splitting cloth, which broadened to 'split, crack, rupture' in general. The 衣 component is written split around 列 rather than on the side.