-havenotalegtostandon;bedonefor;beuntenable;cannotbejustified;cannotholdone'sground;cannotholdwater;(Whatyousaid)doesn'tholdwater.;groundless;ill-founded;ill-grounded;impossibletodefend;unabletoconsolidateone'sposition;unabletogetafooting;unabletostand[maintain]one'sground:
Hehasn'talegtostandforthistheoryofhis.他的这种理论是站不住脚的。
Yourargumentisill-founded.你的理由站不住脚。