premo, spelled p r e m o

has no definition and has never needed one.

Someone made this word and sent it to you. It still means nothing. Make one of your own

why a meaningless word is useful

It is already available.
A word that means nothing has not been used by anyone, so the domain, the handle and the trademark class are far more likely to be free. Meaning is the part that makes a name expensive.
It carries no baggage.
A name built from real words drags those words into every market you enter, including the ones where they mean something you did not intend. A meaningless word arrives with nothing attached.
It becomes yours.
Every famous brand name was nonsense before it was a brand. The meaning was added afterwards, by the company, at considerable expense. This is simply the beginning of that.