I define ghosting is intentionally not responding to someone who you had romantic engagement with earlier (from simple conversation all the way to a in person dating and sex)
People at the bare minimum of age 25 (more like 30) should be able to answer this better. They can remember times ago
My theory is digitization has made all of this much worse. People can ghost because they can quickly fall back on social media to get their sugar high attention needs met. 20+ years ago that wasn’t a possibility. 10+ years ago things starting sadly shifting.