> for example the V2 was technically a hypersonic missile.

The V2 was not a hypersonic missile, it was a ballistic missile that had a predetermined flight path that was easy to predict. The distinguishing factor of hypersonic missiles is that they do not require a ballistic trajectory to achieve their speeds (and are hence, much harder to detect) and they maintain maneuverability throughout their entire flight path.

https://www.sipri.org/commentary/topical-backgrounder/2022/m...

> The ancestor of ballistic missiles, Germany’s [...] V-2 was first launched in the 1940s. During ascent, it could reach a speed greater than Mach 5 and could do so again momentarily on its way back down. But, no one would claim that the V-2 was a hypersonic missile. In a similar vein, should one apply this label to modern intercontinental ballistic missiles that reach speeds beyond Mach 20 at ascent and re-entry?

> Certainly not, and there are other characteristics commonly cited when defining ‘hypersonic missiles’. However, while a combination of defining characteristics is increasingly adopted among experts, hypersonic missiles are often not well understood within public discussions in politics and the media [...]. The US-based Missile Defense Advocacy Alliance states that ‘hypersonic weapons refer to weapons that travel faster than Mach 5 (~3800mph) and have the capability to maneuver during the entire flight.’

How about don't call stuff that travels faster than sound a "fasterthansoundic missile" if you don't want people to confuse it with all other old stuff that also travels faster than sound!