RSS is an abbreviation for:

• RSS, a group of XML based web-content distribution and republication (Web syndication) formats primarily used by news sites and weblogs (blogs).
  • the Rich Site Summary is also known as RSS 0.9x (although many weblog feeds are full-text, not summaries)
  • the RDF Site Summary is based on Netscape's short-lived RSS 0.90, which used the W3C Resource Description Framework Standard; this is also known as RSS 1.x
  • the Really Simple Syndication is also known as RSS 2.x
  • sometimes, by casual (though incorrect) use, alternative syndication protocols, such as Atom.
• Rashtriya Swayamsevak Sangh, a nationalist right-wing Hindutva group in India.
• Resident set size
• Radio Service Software, a proprietary suite of programs sold by Motorola for use with their transceivers.
• Repetitive stress syndrome, a medical disorder.
• Republic of Singapore Ship, all commissioned ships of the Republic of Singapore Navy start with RSS, meaning "Republic of Singapore Ship".
• Rochester Subway