How to Write 垢 (gòu) — Meaning “dirt; filth”

Imagine that after (后) you walk on soil (土), your shoes become covered in dirt — that dirt is 垢. You can also think of the phrase "dirt behind" to link the sound and meaning.

The left radical 土 is written with three strokes: horizontal, vertical, and a final horizontal where the bottom stroke changes to a rising slant (提). The right part 后 has a horizontal stroke at the top, then a downward left-slanting stroke, and the mouth component (口) should be centered and slightly smaller than the upper part. A common mistake is making the mouth too large or misaligning the left and right halves.

垢 (gòu) means dirt or filth, while 圻 (qí) refers to the border of a territory or the region of an ancient state, and 圼 (niè) is an archaic character for a narrow defile or a mountain pass. Visually, 垢 has the component 后 on the right, whereas 圻 uses 斤 (axe) and 圼 uses 日 (sun) or 旦, so the right-side shape clearly distinguishes them.

垢 appears in compound words like 污垢 (wū gòu, general dirt/grime), 牙垢 (yá gòu, dental plaque/tartar), and 油垢 (yóu gòu, greasy dirt). It is not a common standalone character in daily speech but is frequently used in hygiene, cleaning, and medical contexts. Culturally, 垢 often implies stubborn or accumulated filth that requires effort to remove.

Common words containing 垢 include: 污垢 (wū gòu) — Dirt / Grime; 牙垢 (yá gòu) — Tartar / Dental plaque; 油垢 (yóu gòu) — Grease or grime.