A stakeholder, in its original sense, is someone who has a stake in an outcome — someone who will be affected by a decision or who has an interest in how something turns out. This is a useful concept. Identifying who has a stake in a decision helps ensure the right people are consulted and the right impacts are considered.
In practice, "stakeholder" has come to mean almost everyone.
The expansion
The word expanded because it is easier to say "stakeholders" than to name specific people or groups. "We need to consult our stakeholders" is a sentence that sounds thorough without specifying who those stakeholders are, what their interests are, or how they will be consulted.
When stakeholder means everyone, it means no one in particular. A stakeholder engagement plan that does not name specific stakeholders is not a plan. It is a category.
The stakeholder meeting
The stakeholder meeting is a meeting that includes everyone who might have an interest in the topic. Because "might have an interest" is a broad criterion, the meeting is large. Because the meeting is large, it is difficult to make decisions. Because it is difficult to make decisions, a smaller follow-up meeting is scheduled with the people who actually need to decide.
The stakeholder meeting has produced a meeting for the actual stakeholders.
How to use the word usefully
When you say "stakeholders," name them. "The stakeholders for this decision are the finance team, the operations lead, and the regional managers" is more useful than "the relevant stakeholders." It tells you who to consult, who to inform, and who will be affected.
If you cannot name the stakeholders, you have not yet identified them. That is the work to do before the meeting.
The question: When someone says "we need to align with stakeholders," ask: "Which stakeholders specifically?" The answer will tell you whether the stakeholders have been identified or whether the word is a placeholder for work that has not been done.