[masraum]

To me a blown seal is a seal that no longer, uh, seals, aka, it leaks.

To me, a shock should be a sealed system whether it's a gas charged shock or an oil filled shock, if the gas has escaped, or the oil is leaking out, then it's leaking, and therefore, blown.

To me, a shock that's blown is pretty catastrophic for a shock, compared to just high miles and no longer damping as much as it used to due to wear on the inside.

Still, a blown shock is not that big a deal. You can drive cars with no shocks at all (assuming they are shocks and not struts or coilovers).

To me, worn shocks aren't leaking and/or haven't lost their gas charge, but may need to be replaced. Blown shocks are leaking gas or oil (or both) and need to be replaced