sheepish : 1.
“His expression was sheepish.”
The joy of sheepish is that it really DOES come from ‘like a sheep’ – and dates back to Middle English (1150-1200, a quick google tells me). And it is a good word to say. Sheepish. Sheepish. Sheeeeeeeeeeeeeeeeeepish.
I’ll shut up now, she said sheepishly 😉