Acronyms

In your article on the rules of the Sages, I came across acronyms. I would appreciate it if you could explain to me what Sho’at and Ko’a are.
I will quote:
“It should also be noted here that according to the law, the Sages only remove a thing from the Torah in Sho’at or in the Ku’a for a time, like Elijah on Mount Carmel (see Rabbi Benedir 202b, who says that according to the rules, removal in the Ku’a is also possible for a time). And here, in certain cases we find in the Rishonim the authority of the Sages to remove a thing from the Torah even in the Ku’a for a time. It is clear that such a step is taken in situations where there is a critical need, and it is seen that the Sages can deviate from the formal rules that allow them to remove only in Sho’at or in the Ku’a for a time. If so, even in our time there is room to do so if the time requires it.”
Thanks in advance!