  We investigate the effect of geometrical frustration on the competition
between the Kondo coupling and the Ruderman-Kittel-Kasuya-Yosida interaction in
Kondo lattice systems. By variational Monte Carlo simulations, we reveal an
emergent quantum phase with partial ordering in which the frustration is
relieved by forming a magnetic order on a sublattice and leaving the rest in
the Kondo screening with spin-singlet formation. The role of quantum
fluctuations and spin-charge interplay is elucidated.
