Do you have an economic or legal reference for that definition of "monopoly"?
Since search engines are all free to use, many of the criteria of a monopoly seem hard to apply, but the classic defintions I'm familiar with include things such as "no reasonable substitute" which is not the case for Google Search.
Courts do not require a literal monopoly before applying rules for single firm conduct; that term is used as shorthand for a firm with significant and durable market power — that is, the long term ability to raise price or exclude competitors. That is how that term is used here: a "monopolist" is a firm with significant and durable market power.
Since search engines are all free to use, many of the criteria of a monopoly seem hard to apply, but the classic defintions I'm familiar with include things such as "no reasonable substitute" which is not the case for Google Search.