Definition of RSS in English:

RSS

noun

Computing
  • [mass noun], [usu. as modifier] A standardized system for the distribution of content from an online publisher to Internet users.

    ‘creating an RSS feed that others can subscribe to’
    ‘I have eight blogs in my iPhone RSS reader’

Origin

1990s: originally an abbreviation of RDF Site Summary, later interpreted as Rich Site Summary, and now usually as Really Simple Syndication.