I will give you Kittle's definition.
"Adam as the first man is mentioned in 1 Tim.2:13-14 in connection with the order of the community set out in 1 Tim. 2:1 - 3:16. In the section which deals with the right conduct of the woman in the service of God (2:9-15) the demand that she should be subordinate to man (2:12) is given as a basis in early biblical history. This establishes the supremacy of man at creation by the fact a. that he was created first (2:13), and b. that Eve was first deceived (2:14)... The order of God at creation is still His will for the community (cf Mk. 10:6).
Usurping then means for the woman to become her own authority. It is clear that women have a role and to step outside that role is to step outside the creative order. A clear example of this is found in Rev. 2:20 where a woman has usurped authority and is teaching men.
Ok. I thought usurping was taking by force authority over someone.