I use market manipulation to mean just that, someone manipulating the market in whatever way. I'm not familiar with the legally-oriented meaning of this term.
Market cornering is classic market manipulation. Google uses every asset at their disposal to maintain their 98%+ death grip on the search markets. The list of competitors bought, stifled, legally crushed, or absorbed is probably endless. The search market is thoroughly cornered.
I used the phrase intentionally and specifically. Advertising isn't always market manipulation, but it can be and is used to that purpose.
Google uses advertisement and content "curation" to manipulate consumers. This results in product preference, purchasing behavior, and market conditions favorable to Google and/or unfavorable to Google's competition. This includes siloing consumers in political bubbles and manipulation of narratives through the deliberate selection, order, and pacing of content exposure based on the intent of Google's shotcallers.
The reinforcement cycles inherent to their algorithms are used to manage the information made available to vast numbers of people, with highly detailed behavioral profiles used to achieve behavioral outcomes, whether it's buying something, voting, or preferences for or against particular policies or candidates.