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general::
Phrase(s): on shaky ground [and] on dangerous ground
Fig. [of an idea or proposal] on an unstable or questionable foundation; [of an idea or proposal] founded on a risky premise. • When you suggest that we are to blame, you are on shaky ground. There is no evidence that we are at fault. • The case for relying solely on nuclear energy seems to be on dangerous ground.
McGrawhill's American Idioms And Phrasal Verbs