The Military Interdepartmental Purchase Request (MIPR) is a method for transferring funds amongst U.S. military organizations. It allows for multi-organizational cooperative efforts to be performed, rather than limiting funding to a single organization.
MIPR is defined in the US government's Code of Federal Regulations, 48CFR253.208-1, DD Form 448, Military Interdepartmental Purchase Request.
In colloquial parlance it is pronounced mip-per and is used both as a noun (I received their MIPR yesterday,) and as a verb (Did you MIPR the funds to their office yet?)
References
Military Interdepartmental Purchase Request Wikipedia(Text) CC BY-SA