The purpose of this article is to consider the concept of homophobia from a psychosocial perspective. After a brief history of the emergence of the concept of homophobia and other concepts that have emerged over time to clarify the idea, we will discuss what these concepts provide in terms of framing and defining the phenomenon, and the questions this framing and defining raise, in turn, about this concept. The various ways of measuring homophobia will also be examined, in order to identify the limitations of these tests and what they teach us about the phenomenon of homophobia. Wing these as starting points, we will try to redefine homophobia as a complex system that brings together several concepts (heterosexism, sexual prejudice, heteronormativity, sexism and male dominance). This system-based definition of homophobia will lead to a more nuanced understanding of various situations involving discrimination, inequality and violence, and will uncover violent situations that remain hidden by the current understanding of homophobia. (C) 2016 Published by Elsevier Masson SAS.