Combining macroscopic measurements, neutron scattering, and modeling, we identify in the ${\mathrm{GeFe}}_2{\mathrm{O}}_4$ spinel a correlated paramagnetic state resulting from the predominance of third-neighbor antiferromagnetic interactions. These interactions materialize four interlaced families of triangular planes with 120° spins emerging from the underlying pyrochlore lattice. At lower temperatures, a phase transition occurs to a noncoplanar spin structure that is characterized by six propagation vectors. This unusual multi-$q$ order is triggered by the presence of weaker interactions up to the sixth neighbors. The system is remarkably successful in coupling the different triangular planes while maintaining their two-dimensional 120° order. Our Letter highlights the hierarchy of interactions involved in ${\mathrm{GeFe}}_2{\mathrm{O}}_4$, which is singular among spinel compounds since first-neighbor interactions are only a small fraction of the dominant third-neighbor ones.

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• Frustrated magnetism
• Magnetic order
• Noncollinear magnets
• Single crystal materials
• Neutron scattering