Outside Art. 21 of the Charter of Fundamental Rights, EU non-discrimination law is characterized by a closed list of discrimination grounds as defined in the TFEU and in secondary law. The Court of Justice has held that this list cannot be expanded through case law. Accordingly, the meaning given to the relevant grounds (e.g. « sex », « sexual orientation », « ethnic origin ») is particularly important in practice. The lecture will focus on the meaning of discrimination grounds under EU law, in particular as defined through the case law of the Court of Justice. The lecture will also touch on the combination of grounds in the framework of multiple discrimination.