The cyberspace appropriation of an authentic user’s identity by nonauthentic users, causing fraud or attempted fraud, in some cases, and causing critical infrastructure breakdowns in other cases. Spoofing can also target nonuser-based entities. For instance, an IP address can be spoofed to appropriate the identity of a server and not a human (user).
Schell, B.H. and Martin, C. Contemporary World Issues Series: Cybercrime: A Reference Handbook. Santa Barbara, CA: ABC-CLIO, 2004.