In the context of high-temperature superconductivity: a conventional superconductor.

In a conventional superconductor, the electronic fluid cannot be resolved into individual electrons.

Such a high transition temperature is theoretically impossible for a conventional superconductor, leading the materials to be termed high-temperature superconductors.

Having a transition temperature that is a larger fraction of the Fermi temperature than for conventional superconductors such as elemental mercury or lead.

In a high-T superconductor, the mechanism is extremely similar to a conventional superconductor.

Among the interesting properties recently discovered in fullerenes is their ability to conduct electricity without resistance (superconductivity) at temperatures higher than those of conventional superconductors.

Even that was a scientifically noteworthy accomplishment - conventional superconductors up to that point had topped out at about minus-418.

In conventional superconductors, an attraction is generally attributed to an electron-lattice interaction.

In conventional superconductors, this attraction is due to the electron-phonon interaction.

Though generally believed to be a conventional (phonon-mediated) superconductor, it is a rather unusual one.