牢

• Pinyin: láo
• Hanzi breakdown: 牢 = 宀 (roof) + 牛 (cow), originally animal pen, extended to firm/prison

Meaning

Firm; secure; prison; pen for animals. Describing something solidly fixed or a place of confinement.

Primary modern usage is in compounds: 牢固 (firm/solid), 牢记 (firmly remember), 监牢/牢房 (prison cell), 牢骚 (complaints/grumbling). As standalone adjective, means firm/secure. 牢骚 is especially common: 发牢骚 (to gripe/complain).

Examples

1. 这些教训我会牢牢记住，绝不再犯同样的错误。 I'll firmly remember these lessons and never make the same mistakes again.
2. 这把椅子虽然旧了，但还很牢固，坐着完全没问题。 Although this chair is old, it's still very sturdy; there's no problem sitting on it.
3. 他整天发牢骚，抱怨工资低、压力大，但从不想办法改变。 He complains all day, grumbling about low pay and high pressure, but never thinks of ways to change.

Usage Guide

Context: memory, construction, complaints

Tone: varied

Do Say

• 这个道理要牢记在心。(You must firmly remember this principle.)
• 别老发牢骚了。(Stop complaining all the time.)

Don't Say

• 单独用牢表示监狱 (Say 监狱, 监牢, or 牢房 for prison — standalone 牢 sounds archaic or literary)

Origin & History

Originally pictograph of a pen/enclosure for animals (牛 cow inside 宀 shelter). Extended to mean secure/firm, then to prison.

Cultural Context

Generation: All ages

Social background: Universal