How to Write 垓 (gāi) — Meaning “boundary; ten billion (ancient)”

Imagine a battlefield (土 for ground) with a loud 'HIGH' sound (亥 sounds like 'high' in English) — the center of the battlefield (垓心) is a high-stakes area. Alternatively, think of 'earth' (土) and 'ten billion' (垓's ancient meaning) as a huge amount of dirt forming a boundary. This connects the visual parts to the meaning of a place or limit.

Write the left radical 土 first (horizontal, vertical, horizontal), then the right part 亥: dot, horizontal-left stroke, left-falling, horizontal hook, left-falling, dot, right-falling. Common mistakes include making the 土 radical too wide or misaligning the 亥 component so it looks like 孩 without the child radical. Keep the left side narrow and the right side balanced, with the final diagonal stroke (捺) extending slightly below the left.

垓 (gāi) uses the earth radical 土 and means 'boundary' or 'center of battlefield,' while 圻 (qí) also has 土 but means 'boundary of a thousand miles' and is pronounced differently. 圼 (niè) is a rare character meaning 'to break' or 'a kind of tree,' and it has a different right component (圼 instead of 亥). Visually, the right parts are distinct: 亥 (hai) vs. 斤 (jin) in 圻 vs. 日 (ri) plus other strokes in 圼.

One of the most famous uses is in the place name 垓下 (Gāixià), where the historic Battle of Gaixia took place in 202 BCE, ending the Chu–Han Contention. The word 垓心 (gāi xīn) refers to the 'center of a battlefield' in classical literature. While 垓 is not common in daily modern Chinese, it appears in ancient texts and poetry to describe vast boundaries or the whole world (八垓).

Common words containing 垓 include: 垓下 (gāi xià) — Gaixia (place name); 垓心 (gāi xīn) — center of a battlefield; 八垓 (bā gāi) — The whole world.