Preons

Part of speech: noun

Definitions

1. Hypothetical subatomic particles proposed as the building blocks from which quarks and leptons are thought to be constructed
2. Theoretical sub-particles that some physicists suggest could be the fundamental components underlying known quarks and leptons
3. Speculative elementary entities postulated in particle physics as the smaller constituents out of which quarks and leptons might be formed

Etymology: "Preons" is the plural of "preon", a term coined in 1974 by the physicists Jogesh Pati and Abdus Salam for hypothetical particles thought to be smaller than the quarks and leptons that make up matter. The name was built from the prefix "pre-", meaning "before" or "earlier", and the suffix "-on", the ending physicists had already attached to particle names such as "electron", "proton" and "neutron". Together they signal a particle that would come before the known ones in the chain of building blocks. The idea was a proposal rather than an observed discovery. Pati and Salam suggested that quarks and leptons might themselves be composed of more basic constituents, and "preon" became the name for those constituents. No preons have been detected, so the word still names a theoretical entity.