ity |
ion |
As a noun ion is
ion (
electrically charged atom).
solid |
ity |
Ity is likely misspelled.
Ity has no English definition.
As an adjective solid
is in the state of a solid; not fluid.
As a noun solid
is a substance in the fundamental state of matter that retains its size and shape without need of a container (as opposed to a liquid or gas).
As an adverb solid
is solidly.
As an acronym SOLID
is acronym of Single responsibility Open-closed, Liskov substitution, Interface segregation and Dependency inversion|lang=en When followed, the created system will be more likely easy to maintain, and extend over time.