If you would like to prevent a specific column from being displayed in the “add new item” form on a custom list, there’s a pretty neat way to do this. Navigate to the list settings of your custom list, and set “allow management of content types” to true. After that, you’ll see a content type called “Item”, open it and select the column you’d like to hide. There are three options: required, optional and last but not least: hidden!
Selecting the third option will hide this column in all forms, of course you can still use it as a field to store a value.