  Crystal structure, thermodynamic properties, and adiabatic demagnetization
refrigeration (ADR) effect in the spin-7/2 triangular antiferromagnet
KBaGd(BO3)2 are reported. With the average nearest-neighbor exchange coupling
of 44 mK, this compound shows magnetic order below $T_N = 263$\,mK in zero
field. The ADR tests reach the temperature of $T_{min} = 122$ mK, more than
twice lower than $T_N$, along with the entropy storage capacity of 192
mJK$^{-1}$cm$^{-3}$ and the hold time of more than 8 hours in the PPMS setup,
both significantly improved compared to the spin-1/2 Yb$^{3+}$ analog. We argue
that KBaGd(BO3)2 shows a balanced interplay of exchange and dipolar couplings
that together with structural randomness and geometrical frustration shift
$T_{min}$ to well below the ordering temperature $T_N$, therefore facilitating
the cooling.
