Embarrassed, as by consciousness of a fault: a sheepish grin. (adjective)
Meek or stupid.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "sheepish" in a sentence
"Even the look the animals adopt when chewing grass has led to the phrase "sheepish"."
"They shared a long smooch before breaking out in sheepish grins."
"Josh bore it all with an expression of sheepish delight."