How to Write 囟 (xìn) — Meaning “Fontanelle (top of the head)”

Picture a baby's head as a square, and the soft spot on top is shaped like a plus sign or cross. The character 囟 looks just like that: a square head with a cross inside, reminding you of the fontanelle.

Start with the outer enclosure (囗) as a square in three strokes, then add the inner cross: a horizontal stroke from left to right, followed by a vertical stroke through the center. A common mistake is letting the inner strokes touch the top or bottom of the square; keep them separate and centered.

囟 has a cross (+) inside a square, 囚 has a person (人) inside a square (meaning prisoner), and 四 has two inner strokes that form a window-like shape (meaning four). Focus on the inner pattern: cross, person, or two short lines.

囟 is a specialized character found mostly in medical or anatomical terms, such as 囟门 (xìn mén), which refers to the fontanelle on a baby's head. It is not common in daily conversation but is important for parents and healthcare professionals discussing infant skull development.

Common words containing 囟 include: 囟门 (xìn mén) — Fontanelle (soft spot on a baby's head); 囟脑门 (xìn nǎo mén) — Fontanelle / Top of the head; 囟骨 (xìn gǔ) — Parietal bone / Skull bone.