For those who may be having a conniption fit at this very moment whilst trying to understand what a conniption fit is, the answer may be found here. Contributors to OST will be relieved to learn that such an ocurrence is not to be confused with a hissy fit or temper tantrum, but is further defined thus:

A conniption fit, by comparison, could be triggered whenever an otherwise rational person is confronted with an irrational set of circumstances. Under those conditions, an emotional response may very well be anticipated, although having a conniption fit could be translated as a momentary lapse of reason. source - Conniption fit