Why: Mary said her parents had a "conniption fit" when she got kicked out of flight attendant school.
Answer: A fit of rage, hysteria, or alarm. The word might be a corruption of the word "corruption."
It is even possible that the phrase "conniption fit" arose from the Yiddish language, since Yiddish words like knish are routinely pronounced with both the hard K and N sounds.Source: Merriam Webster, WiseGeek
The More You Know: Mary also introduced me to the term "hitch in the giddy-up," which some say means to not feel well, but she uses (and I like better) to mean something that will slow down operations, to be used like: "Here's the catch." I also sometimes say, "Here's the hiccup."