knock-down-drag-out
adjective [ before noun ] US uk/ˌnɒk.daʊn.dræɡˈaʊt/ us/ˌnɑːk.daʊn.dræɡˈaʊt/
（长时间）激烈的（斗争或讨论）
a knock-down-drag-out fight or argument is very serious and continues for a long time
Look, I don't want to get into a knock-down-drag-out fight with you over this, so let's forget it. 听着，我不想跟你就这个问题纠缠争论，咱们忘了这件事吧。