填充
tián chōng · HSK 7
to fill up; to stuff; to fill in a blank space
🛋️ 填 = fill + 充 = fill up; doubling up the idea of filling = stuffing/padding
填 (tián) means to fill in, like filling a hole; 充 (chōng) means to fill up or supplement. Stack both fill-verbs and you get padding — material stuffed in to fill empty space, like cushion stuffing or filler text.
填 — earth 土 + 真 (zhēn, phonetic)
填 is a semantic-phonetic compound. The 土 (earth) radical signals the meaning—filling in with soil—while 真 supplies the sound (originally close to 'tian'). The original sense was to stuff or pack a hole with earth, later broadened to filling in any gap, form, or blank.
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'.