  To search for novel spin-charge coupled phenomena in the strongly correlated
electron system on a frustration lattice, charge transport and dynamics have
been investigated for the hole-doped spin-glass (Mott) insulator
(Y$_{1-x}$Cd$_{x}$)$_{2}$Mo$_{2}$O$_{7}$ with pyrochlore structure. Coincident
with the disappearance of spin-glass state by hole doping, a diffusive metallic
transport with strongly renormalized electron mass shows up with no long range
spin order, which is caused by strong antiferromagnetic spin fluctuation due to
the geometrical frustration.
