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.