Definition of "soluble" How to define "soluble" in chemistry?

For example, in 1:1 v/v, benzene does not mix with water, i.e. insoluble. Common sense.

However, in an analytical procedure, it called for making a "saturated" aqueous solution of benzene, which is about 1.5 g/L. So, benzene actually  has some solubility in water.

So, my question is, is there an official definition of "soluble"?
IUPAC defines "Solubility", but not "soluble". There is no single definition because there is no single meaning. The reason there isn't a single meaning is because it is useful to have different meanings in different contexts. (This is true of almost all words.) According to Wikipedia, 0.1g per deciliter is a common ceiling for insolubility. I've seen various values for the lower value for labeling a compound "soluble". I've seen 1g, 2g, 3g, 5g and possibly more claimed to be the (arbitrary) floor. I don't see any reason to call for standardization, because the use for such a property is varied and diverse.