There is no right or wrong definition of a runner. I personally call someone a runner if they run consistently year after year. If you're 'good' in your age group, it also helps to identify as a runner. BQ is one such criteria. I haven't run Boston (I will eventually, just avoided the travel) yet but am almost half an hour faster (latest PR 2.43 at 43 years of age) than the required qualifying time so I'm absolutely a runner even though I've not done Boston yet.