A sheepish reply is a response that is made in an embarrassed or timid manner. The two crossword solutions for this term are BAA, which is three letters, and BAABAA, which is six letters. BAA is the sound that sheep make, and BAABAA is a repetition of the sound. Both of these solutions are indicative of a sheepish reply, as they represent the sound of sheep, which is often associated with timidity.