There is no single word. You have to construct a whole sentence. That's when I have extra-curricular activities. I'm having extra-curricular activities then. 你业余时间通常都做什么？= What are your extra-curricular activities? 业余 = spare time / amateur / extra-curricular All three words are different in English.

Do you mean: What do you usually do in your spare time?

You can decompose the word into 业, which generally refers to employment/profession, and 余, which means can mean "remaining" or outside of. Combined, therefore, the word means spare time. Eliot is also correct, however, that the translation depends on the usage. For example, your sentence "你业余时间通常都做什么？" could be translated as "What do you usually do in your spare time?"

一楼的正解

对的 你可以用spare time的