The story
From the initials of the names of the physicist theoreticians who predicted this superconducting phase: Peter Fulde, Richard Ferrell, Anatoly Larkin, and Yuri Ovchinniko.
Etymology from Wiktionary, CC BY-SA 4.0.
FFLO phase
Today it means: A type of superconducting phase, characterized by the presence of Cooper pairs with nonzero center-of-mass momentum and a spatially non-uniform superconducting order parameter. Full definition →