  We demonstrate that geometric frustration and long-range interactions both
promote order-by-disorder in the antiferromagnetic transverse-field Ising model
on the ruby lattice. To this end we investigate the quantum phase diagram for
truncated $J_1$-$J_2$-$J_3$ Ising interactions. In the low-field limit we
derive an effective quantum dimer model, analyzing how the extensive
ground-state degeneracy at zero field is lifted by two distinct
order-by-disorder scenarios. We support our analysis by studying the
gap-closing of the high-field phase using series expansions. For $J_2>J_3$, we
find an emergent clock-ordered phase at low fields, stabilized by resonating
plaquettes, and a 3d-XY quantum phase transition to the polarized high-field
phase. For $J_3>J_2$, an order-by-disorder mechanism stabilizes a distinct
$k=(0,0)$ order and a quantum phase transition in the 3d-Ising universality
class is observed. In contrast to the triangular lattice, on the ruby lattice
algebraically decaying long-range interactions favor the clock-ordered
low-field phase and therefore allow a robust implementation in existing Rydberg
atom quantum simulators.

Strongly Correlated Electrons;Quantum Gases;Quantum Physics