executable vs actionable vs doable

I am working on the user interface of an application which treats any piece of information that can be acted upon as an 'executable':

• a program can be executed by the operating system
• a code script can be executed by an interpreter
• a todo can be done by a person
• an activity can be participated in by a person
• ...

Within the application code, the nomenclature is based around the word stem 'execut' using the following logic:

An execution is the process of an executer executing something executable.

The problem: When using this nomenclature in the application's user interface, most test users do not really understand this type of abstraction and are confused about why their todos, activities, code files, apps, programs etc. are basically displayed and handled the same way.

A potential solution would be to use other word stems:

• 'act': an action is the process of an actor acting upon something actionable
• 'do': a ??? is the process of a doer doing something doable

My questions: Are there any other word stems suitable in this case? If not, which of the given stems conveys best what I'm trying to convey?

OP treats the in-code naming as settled and asks only about the user-facing label. Fair enough, but the bullets show the metaphor straining even in code. Nobody executes an activity, they participate in it. Any stem general enough to cover a binary and a soccer practice reduces to bare grammar, a subject verbing an object, which is why act feels no better than execut. The deeper issue is that testers are not confused by the word. They are confused because a todo and a program look identical on screen. That is a rendering problem and no noun will fix it. If possible, give each type its own icon and its own verb on the button. Keep the abstraction in the code.