Using gender analysis helps to see the gender biases in the concept of 'terrorism' that are at the apex of its definitional concerns, political problems and moral ambiguities. This chapter examines the definitional problem of terrorism, not just for inconsistencies but also for how what or who is included in common definitions and how these inclusions/exclusions are gendered. It points out one of the important elements of using gender analysis to theorize terrorism: understanding how people identified as terrorists are gendered in media and scholarly discussions of their actions. The chapter discusses genderings in counterterrorism theory and practice. Feminists would thus note that 'terrorist' is also a heavily gendered term used to devalorize politically violent actors, replicating the Westphalian binary of masculinized/legitimate states with the monopoly on violence against feminized/illegitimate non-state actors without access to sanctioned forms of violence.