In my job, I need to use materials that have a mil spec; that means it's literally military grade, but it's just saying that it meets or exceeds a certain specification for X product that is used in the military in some way. IMO, if something says 'military grade', but isn't listing the mil spec(s) that it complies to, then it's essentially meaningless.

I do have a compass that I think was advertised as military grade. It's the same lensatic compass that is currently used by the military (...when they aren't using GPS...), except that it doesn't use tritium on the face. The half-life of tritium is about a decade, so it didn't seem like a great idea to pay a ton extra for something that would barely glow in the dark in 20 years or so.