Pointing out that the IRS includes certain things in payment that you don't isn't a claim that some definition they use limits the usage of the word payment. The point is not that everybody should use the IRS definition for words. The IRS provides evidence about what people do in the world; you don't have to (nor was I asking for you to) accept them as the authority.
If I understand your dismissal of definition (1), you are implying that it is significant that definition (2) by contrast only says "money" and uses an example of dollars. I think that's too legalistic and just an artifact of the way things were edited. Dictionaries aren't written to prevent lawyers from finding loopholes, so I don't think you can count on everything being repeated absolutely uniformly. In actual legal documents, they define terms or phrases used repeatedly up front to reduce the repetition, and dictionaries don't seem to customarily do that. So again, definition (1) is evidence about how people behave in the world, not necessarily the definition we are using and from an unimpeachable authority.
No, you do not understand why definition 1 does not apply. The question was: what debt do you owe to Facebook to settle? I claim there is none. Therefore, you are not acting in accordance with definition 1 when providing information to or viewing ads from Facebook.
If I understand your dismissal of definition (1), you are implying that it is significant that definition (2) by contrast only says "money" and uses an example of dollars. I think that's too legalistic and just an artifact of the way things were edited. Dictionaries aren't written to prevent lawyers from finding loopholes, so I don't think you can count on everything being repeated absolutely uniformly. In actual legal documents, they define terms or phrases used repeatedly up front to reduce the repetition, and dictionaries don't seem to customarily do that. So again, definition (1) is evidence about how people behave in the world, not necessarily the definition we are using and from an unimpeachable authority.