拡充
かくじゅう · kakujuu · JLPT N2 · noun
expansion
🎈 拡 (kaku = enlarge) + 充 (juu = fill up) = expansion: grow bigger and fill out
拡 (kaku) means enlarge, as in 拡大. 充 (juu) means fill or supply, as in 充電 (charging). Together they describe expanding and filling out a space or capacity.
充 — 育 (raise/grow) on top of 儿 (legs/person)
Originally depicted a person walking forward, suggesting movement and advancement. The form combines a growth element above with a person below, evoking the sense of being filled up or made full as one grows. Over time, the meaning shifted from 'go forward' to 'fill, fulfill, abundant'.