From the Wiki article, the UN definition of Genocide is met if...
...any of the following acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, as such:
(a) Killing members of the group; (b) Causing serious bodily or mental harm to members of the group; (c) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part; (d) Imposing measures intended to prevent births within the group; (e) Forcibly transferring children of the group to another group. — Convention on the Prevention and Punishment of the Crime of Genocide, Article 2[5]
I'm not a fan of China, but the UN bar for genocide is so low that it's essentially meaningless.
The word itself means gene-killing.
Whether china is actually trying to wipe out or is being oppressive isn't clear when the UN definition is used.