I agree. We don't have an equivalent term because there is no equivalent concept in the British higher education system. As Paul says, you just study what you study. In the past, we'd use the verb 'read' for the subject of a person's degree. ( e.g. "My grandfather read classics at St Andrews") That's outdated now, so we'd just say, "What's your degree?", "What are you studying?" or even, more informally, "What are you doing at uni?".