It’s also historical, Haydn. I grew up with the term ‘flash’ simply meaning success on the first go, but not onsight because of prior knowledge. Nothing wrong with redefining something, but that’s my ‘curiously definitive’ view (to Alex’s mind).
That hardly addresses the grey areas though. Should it be ground up? Abseil past ok, but not fondling the holds? The term originates in a pre-video era, where most info would have been word of mouth- hidden pocket, filed-down RP2 etc so today’s avalanche of info was not a factor to take into account.
Today’s wads need to reach a consensus on what’s cricket and agree which terms correspond.