1.bellow的基本意思是“咆哮”“发出吼叫声”，尤指公牛等因痛苦而“咆哮”，是不及物动词。
2.bellow还可指人“大声吼叫，愤怒地说出”，可用作及物动词，接所说出的内容(sth,that-clause,speech)作宾语，表示“对某人吼叫〔说〕”须说at sb。
3.bellow out意为“（愤怒地）说出”；bellow with意为“因…而吼叫”。

bellow out(v.+adv.)
(愤怒地)说出；大叫say loudly or angrily;shout
▲bellow out
The wounded lion bellowed out.受伤的狮子发出怒吼。
The bull has been bellowing out all morning. 公牛整个上午大吼不止。
▲bellow sth ⇔ out
They bellowed out a laugh.他们哈哈大笑。
They bellowed out a song. 他们高唱歌曲。
Finally, he bellowed out a famous poem.最后，他大声背诵了一首著名的诗。

bellow with(v.+prep.)
因…而吼叫shout for
▲bellow with sth
He bellowed with pain when the tooth was pulled out.当牙齿被拔掉时他痛得大声呼叫。

用作不及物动词
▲S+～(+A)
After a while the bull began to bellow in pain. 过了一会儿公牛开始痛苦地吼叫。
She bellowed with pain. 她痛得大叫。
They bellowed at her to stop but it was too late.他们吼叫着让她停下，但太晚了。
He bellowed before the dentist had even started.牙医还未动手他就大叫起来。
用作及物动词
▲S+～+n./pron.
The man bellowed a laugh.那个人哈哈大笑。
He bellowed his answer. 他大声回答。
The coach bellowed instructions from the sideline.教练在场边大声发号施令。
▲S+～+that-clause
He bellowed that he would never take back his words. 他吼叫着说他决不收回他的话。