壘

Ideogrammic compound:

土 (흙 토, “earth, soil”) repeated three times — denotes piled-up earth or embankments.

田 (밭 전, “field”) enclosed within — suggesting a fortified area surrounded by earthworks.

Thus, originally a pictograph of a fortified encampment or fortress built with earth walls.

堡壘 (보루) — stronghold, fortress

壘壁 (루벽) — rampart, defensive wall

壘門 (루문) — fortress gate

三壘 (삼루) — third base (baseball)

本壘 (본루) — home plate/base

In military texts, 壘 referred to field camps and fortifications built quickly with earth and wood.

In modern Chinese and Japanese, 壘 is the standard character for “base” in baseball terminology.

Korean usage preserves 壘 mainly in Sino-Korean compounds (堡壘, 本壘) rather than standalone.