Wiktionary
n. (context physics English) The superpartner of the gluon.
Wikipedia
In supersymmetry, a gluino (symbol ) is the hypothetical supersymmetric partner of a gluon. Should they exist, gluinos are expected by supersymmetry theorists to be pair produced in particle accelerators such as the Large Hadron Collider.
In supersymmetric theories, gluinos are Majorana fermions and interact via the strong force as a color octet. Gluinos have a lepton number 0, baryon number 0, and spin 1/2.
In models of supersymmetry that conserve R-parity, gluinos decay via the strong interaction to a squark and a quark, provided that an appropriate mass relation is satisfied. The squark subsequently decays to another quark and the lightest supersymmetric particle, LSP (which leaves the detector unseen). This means that a typical signal for a gluino at a hadron collider would be four jets plus missing energy.
However if gluinos are lighter than squarks, 3-body decay of a gluino to a neutralino and a quark antiquark pair is kinematically accessible through an off-shell squark.
Usage examples of "gluino".
The whole kit-and-caboodle of pions, mesons, gluinos, antineutrinos, that whole strange charm of quarkiness, may come to seem a very twentieth-century enthusiasm.