部下
ぶか · buka · JLPT N1 · noun
subordinate
部 (department) + 下 (below): someone in your department who sits under you
部 means section or department and 下 means below or under. Put them together and you get a person in your section who ranks beneath you.
部 — 阝(邑) right + 咅 phonetic
The right-side 阝 derives from 邑 (city/settlement), giving the meaning of a region, district, or administrative division. The left side 咅 supplies the sound. Originally referring to a settlement, the meaning broadened to 'part,' 'section,' or 'ministry.'
下 — horizontal line 一 + mark below
下 is an indicative character: a long horizontal line represents a reference level, and a shorter stroke placed beneath it points to the area below. The original meaning 'below, down' comes directly from this spatial diagram, and it later extended to verbs like 'descend' and 'lower'.