ようものなら
you mono nara
if one dares to; if one should happen to
[If one dares to / If one should happen to]
Connection: Verb volitional form (よう/おう) + ものなら
Usage: Expresses a strong warning that if someone dares to do something, a very negative consequence will follow. Used to emphasize that even a slight action would trigger a terrible result.
Examples:
そんなことを言おうものなら、大変なことになる。(If you dare say such a thing, there will be serious trouble.)
少しでもサボろうものなら、すぐにクビになる。(If you dare slack off even a little, you'll be fired immediately.)
遅刻しようものなら、先生にひどく怒られる。(If you dare be late, the teacher will scold you terribly.)