From BusinessDictionary.com, a definition of Stakeholder:
“A person, group, or organization that has interest or concern in an organization. Stakeholder can be affected by the organizations actions, objectives and policies. Some examples of key stakeholders are creditors, directors, employees, government and its agencies, owners or shareholders, suppliers, union, and the community from which it draws its resources.”
And also a definition of Stakeholder from Wikipedia:
A stakeholder is someone who has an interest in a corporation, and participates in the promotion and creation of a corporation. One who holds strong beliefs in a corporation, participates in the promotion and creation of the corporation through team effort, invests their time, money, resources and assets into the furtherance of the corporation. To be a stakeholder is to have contributed and hence to have had an active stake in the company. To recognize all stakeholders of a company is to recognize the efforts and contributions of all who have contributed to making the company a success.