Knot terminology

Do the terms "capsize" and "spill" mean the same thing?

Specifically, does any one word refer to the way a knot changes shape when
tightened (as the carrick bend does) and is there any term that refers to a
knot becoming mis-shapen and useless (probably because it was tied
incorrectly.)

I'm working with Boy Scouts and would like to be able to talk clearly about
the difference between these two situations.

Thanks.