I think the most widely accepted definition for "garbage collection" is something which frees memory automatically, as opposed to manually freeing memory (or other memory management schemes). In fact, the second paragraph of Wikipedia's page on garbage collection[1] says that "Garbage collection is essentially the opposite of manual memory management, which requires the programmer to specify which objects to deallocate and return to the memory system".

[1]: https://en.wikipedia.org/wiki/Garbage_collection_(computer_s...