What is the suffix that can be added to word solid?

There are several suffixes that can be added to the word "solid," depending on the intended meaning:

Common Suffixes:

* -ity: Solidity (meaning firmness or strength)

* -ness: Solidness (meaning the state of being solid)

Less Common Suffixes:

* -ification: Solidification (meaning the process of becoming solid)

* -ize: Solidify (meaning to make solid)

* -er: Solidifier (meaning something that makes things solid)

The specific suffix you choose will depend on the context and the specific meaning you want to convey.