It has a legal definition you know, and by that definition Iraq has not been occupied since June 2004. That was when Iraq was handed over to the Iraqis.
Per the Geneva Conventions, Iraq is no longer occupied.
Actually, the definition I quoted is a United Nations term definition and according to both their, and the Geneva Convention, definitions, we (US) are still militarily occupying Iraq. If your intent is to quibble over a naive legalese cover/interpretation of terms and responsibilities then you should have avoided bringing up the UN and the Geneva Conventions, as they anticipate, and are designed for the most part, with the specific intent of abbrogating such superficial (and largely domestic political debate) obsfucations.
Article 4 of Geneva Convention IV, if interpreted in the light of its object and
purpose, is directed to the protection of civilians to the maximum extent possible.
It therefore does not make its applicability dependent on formal bonds and
purely legal relations. Its primary purpose is to ensure the safeguards afforded
by the Convention to those civilians who do not enjoy the diplomatic protection,
and correlatively are not subject to the allegiance and control, of the State
in whose hands they may find themselves. In granting its protection, Article 4
intends to look to the substance of relations, not to their legal characterisation
as such
Prosecutor v. Tadic (Case IT-94-1-A) (1999) paragraph 168 (
http://www.un.org/icty/tadic/appeal/judgement/tad-aj990715e.pdf).
Security Council Resolution 1546 of June 8, 2004, endorsed the transferal by June 30, 2004, of authority in Iraq from the CPA to the interim Iraqi government, which had been set up on June 1, 2004. Resolution 1546 deemed that with this transfer of authority, the occupation of Iraq would come to an end. Noting that the presence of the multinational force in Iraq was at the request of the Iraqi interim government, the Council granted that force “the authority to take all necessary measures to contribute to the maintenance of security and stability in Iraq” in accordance with the letters exchanged between the Prime Minister of the Iraqi interim government and the U.S. Secretary of State. The Council viewed these two letters as establishing a “security partnership”—indeed a “full partnership”—between the interim Iraqi government and the multinational force (Article 11).
Resolution 1546 does not elaborate on the international legal obligations to which the multinational force is subject when exercising its authorities. The only reference to this issue appears in the letter of Secretary of State Colin Powell, who asserts that “the forces that make up the [multinational force] are and will remain committed at all times to act consistently with their obligations under the law of armed conflict, including the Geneva Conventions.” The law of occupation, part of which is set out in the Fourth Geneva Convention, requires such a commitment.
Although, by some US considerations the formal occupation of Iraq ended on June 28, 2004, to the extent that the United States and other foreign troops operating in Iraq continue to wield effective control over Iraqis and Iraqi
property, they are bound by this body of laws. As the International Criminal Tribunal - Yugoslavia noted in the Tadic case mentioned above, the Fourth Geneva Convention “does not make its applicability dependent on formal bonds and purely legal relations. . . . Article 4 [of that Convention] intends to look to the substance of relations, not to their legal characterisation as such.”
It is certainly your privilege to play around with technical definitions, but my application of the term "occupation" is both appropriate and de facto founded in International Law and common parlance understandings.
