the.com/fixity
The stubborn refusal of a thing to budge, change, or grow up.
means The state of being firmly fixed, unchanging, or permanently set in place or form.
from From Latin fixus, past participle of figere, to fasten — the same root that pins down a fixation and stakes a prefix.
PhotographyFixing baths grant images permanent fixity against light.
BiologyOld idea: species held eternal fixity, pre-Darwin.
PhysicsA point of fixity anchors moving structures still.