塡

A phono-semantic compound composed of:

土 — semantic component meaning “earth; soil”;

眞 (真) — phonetic component indicating the sound (전 / tián). The character originally referred to filling a hollow or gap with earth.
Semantic development: - to fill a hole with earth; - to fill up or stuff something; - to supply or make up for something lacking.

In modern Korean, the simplified variant 填 is often used interchangeably.
충전 (充塡) — filling; charging (e.g., battery charging) 보전 (補塡) — compensation; replenishment 매전 (埋塡) — filling up with earth; reclamation

Related characters: 補 — to supplement

埋 — to bury; cover with earth

充 — to fill; supply

These characters relate to filling, supplementing, or covering gaps.

塡 is the older traditional form, while 填 became the more widely used form in modern Chinese and Japanese.