WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
the quality of being incapable of mutation
noun.
the quality of being fixed in place as by some firm attachment
Word Usage
"It may be that, on the whole, the idea of fixity prevailed more among thinkers with a religious bias; but for the most part the theories were debated independently of the tenets of any faith, Christian or other."