Baa是一个英文单词，常用于描述绵羊发出的声音。它是一个拟声词，意思是“咩咩叫”。在英语里，Baa通常用于描述绵羊的声音，特别是在儿童故事中。例如，“Mary had a little lamb, its fleece was white as snow, and everywhere that Mary went, the lamb was sure to go. It followed her to school one day, which was against the rule, it made the children laugh and play, to see a lamb at school. And so the teacher turned it out, but still it lingered near, And waited patiently about till Mary did appear. 'Why does the lamb love Mary so?' the eager children cry. 'Why, Mary loves the lamb, you know,' the teacher did reply.” 这首儿歌中就使用了Baa这个词来形容小羊的叫声。因此，如果你在英语中听到了Baa这个词，那么你就可以知道它对应的是绵羊的“咩咩叫”这个意思。