An alias is something that means the same as another, also meaning "also known as" (alias 'aka'). In the LavishScript context, an alias is a way to make your own name for a command, possibly customizing the parameters along the way.
A simple alias is simply a sequence of text to replace a single word. For example, if you want to enter "binds" to mean "bind -list", you would make an alias like so:
Alias binds bind -list
This simply means that when you enter "binds", it will be replaced with "bind -list". Any further parameters you add will get placed after the replacement. This makes it easy to rename commands entirely. For example, you could alias "print" to "echo", and then use "print" exactly as if it were echo.