What does royalist mean?

Royalists are political parties that support the retention of the monarchy. But there are other explanations. China

It originated from the royalist society established by Kang Youwei and Liang Qichao in exile in the late Qing Dynasty. They advocated rescuing Emperor Guangxu from Empress Dowager Cixi and regaining political power in order to restore political reform and realize constitutional monarchy, which was in direct opposition to the revolutionaries who advocated all-round revolution. Usage in contemporary Hong Kong

After 1997, "royalist" or "royalist" was a derogatory term for pro-Beijing political parties, especially those traditional left-wing political groups, such as the DAB, the Liberal Party, the Hong Kong Progressive Alliance (HKPA) and the FTU, because almost all of their motions voted in favour.

I hope it helps you.