Trying to define "growth hacking" is a pointless endeavor at this point. Whatever you think it _used_ to mean, it's become nothing more than an empty marketing buzzword that means a thousand things to a thousand people.
When you use a word like that, you're communicating nothing and giving people a reason to stop taking you seriously.
Whether you mean "growth marketing," "conversion optimization," "a/b testing," "a clever tactic," ... just say that.
The use of a different term is essentially a dog whistle saying "marketing of certain kinds of things" or "marketing by certain kinds of people" but the actual activity described fits completely within the relatively simple and well understood definition of marketing.
When you use a word like that, you're communicating nothing and giving people a reason to stop taking you seriously.
Whether you mean "growth marketing," "conversion optimization," "a/b testing," "a clever tactic," ... just say that.