To suddenly become very angry at someone; to react or respond angrily to someone
I just said I couldn’t go to his party but suddenly he started shouting at me and called me unreliable. I don’t know why he jumped down my throat.
jump down somebody’s throatinformal to suddenly speak angrily to someone
Cambridge Advanced Learner's Dictionary - 4th Edition
jump down sb's throat informal
to react angrily to something that someone says or does:
I made the mildest of criticisms and he jumped down my throat.
© Cambridge University Press 2013
jump down someone's throat in British
to address or reply to someone with unexpected sharpness
jump down someone's throat
Definition of jump down someone's throat
: to respond angrily to someoneHe jumped down my throat when I suggested a different plan.