Isn't the distinguishing feature of a closure that it can capture stuff from the environment?

Unlike a plain function, a closure allows the function to access those captured variables through the closure's copies of their values or references, even when the function is invoked outside their scope.

The term closure is often used as a synonym for anonymous function, though strictly, an anonymous function is a function literal without a name, while a closure is an instance of a function, a value, whose non-local variables have been bound either to values or to storage locations (depending on the language; see the lexical environment section below).

My understanding is that your use of 'capture' matches up with the the use of 'bound' in the description above.

https://en.wikipedia.org/wiki/Closure_(computer_programming)