However, you can use these options depending on the context:
* Familiarity: This is the most common noun form, meaning the state of being familiar with something.
* Familiarization: This noun emphasizes the process of becoming familiar.
* Knowledge: If you are talking about acquiring knowledge of something, "knowledge" can be a suitable substitute.
* Understanding: Similar to "knowledge," "understanding" can be used if you want to focus on the comprehension of something.
The best option will depend on the specific meaning you want to convey.