5 Old HSK word(s): ☊牢 ** C ☊牢固 ** C ☊牢骚 ** C ☊牢房 ** D ☊牢记 ** D
地牢* * 钉牢* * 黑牢* * 监牢* * 记牢* * 土牢* * 亡羊补牢* * 抓牢* * 坐牢* *

Definitions from Unihan Copyright © 1991-2015 Unicode® Inc. All rights reserved.

坐 sit / seat / ride, travel by
牢 prison / stable, pen / secure

Hsk Characters: 牢 *
HSK -Characters and beyond:
GbBig5EngRadMegaTripleMultilingual
牢 7262 + 牢 + + prison / stable, pen / secure 牛 牛 Ox 牛 (RIND) lao2 +

Korean:

牢 + 牢 우리뢰{뇌}
窂 + 牢 우리 로
牢 + 牢 가축우리 뇌
2 NHSK word(s): 牢固* 6 lao2 gu4firm/ secure 牢骚* 6 lao2 sao1discontent/ complaint
KOREAN6000 word(s):
0 KOREAN 2500 New HSK words):
0 KOREAN Sentence(s):