The reconceptualisation of caste discrimination as racial discrimination through the term 'descent' in Article 1 of ICERD enabled the international community to take cognisance of caste discrimination, which it had ignored for a long time. However, the government of India, opposing such reconceptualisation, maintains that 'descent' in ICERD refers only to race and not caste, contrary to the position of UN human rights bodies. Hence, whether 'descent' includes 'caste' is an important hermeneutical question addressed in this article. Based on the distinction between interpretation and application of a treaty, this article argues that India has accepted the application of ICERD to caste discrimination through its conduct and it cannot deny it now according to the principle of estoppel. This article then demonstrates the dynamic interpretation of 'descent', justifying it through the consensus analysis methodology of the ECtHR. Moreover, it is found that 'descent' was associated with 'caste' in British India.