随分
ずいぶん · zuibun · JLPT N4 · adverb
extremely
随分 = follow (随) + one's share (分): beyond your share, so extremely
Originally a Buddhist-flavoured term meaning according to one's lot or capacity. Doing as much as your share allows drifted into meaning considerably, then extremely. Sound hook: zuibun, as in zooey-boon, a boon that goes way too far.
随 — 辶 (walk) + 阝 (mound) + 有 phonetic
随 combines the walk radical 辶 with a phonetic component derived from 隋. The original sense is 'to follow along a path,' from the walking radical suggesting movement after someone. Over time it broadened to mean 'follow,' 'accompany,' or 'comply with.'
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.