It is a wind rating, which is much more meaningful than the gobbledegook dreamed up by stupid reporters.
It's very meaningful to ships. It was originated by a guy studying the effectiveness of cheap low income housing (which is relatively inexpensive to make water-proof, but more expensive to make structurally sound in high winds).
There used to be (and still are but they never talk about them) 3 parts to the rating system.
Wind speed
Barometric Pressure
Storm Surge.
Lately they just seem to be rating storms based solely on wind speed. As in since 2005