牢

firm / sturdy / fold (for animals) / sacrifice / prison

"roof" radical (Kangxi radical 40), occurring in 家, 定, 安 etc, referred to as 寶蓋|宝盖[bao3 gai4]

ox / cow / bull / CL:條|条[tiao2],頭|头[tou2] / newton (abbr. for 牛頓|牛顿[niu2 dun4]) / (slang) awesome

to be imprisoned

prison / dungeon

to whine / to be grouchy

prison

lit. to mend the pen after sheep are lost (idiom) / fig. to act belatedly / better late than never / to lock the stable door after the horse has bolted

a youth without facial hair cannot be relied upon (proverb)

to do prison time (Tw)

strong / firm

(in ancient times) sacrificial animal (cow, sheep or pig)

see 嘴上沒毛，辦事不牢|嘴上没毛，办事不牢[zui3 shang4 mei2 mao2 , ban4 shi4 bu4 lao2]

tight-lipped