  Spin liquid ground states are predicted to arise within several distinct
scenarios in condensed matter physics. The observation of these disordered
magnetic states is particularly pervasive amongst a class of materials known as
frustrated magnets, in which the competition between various magnetic exchange
interactions prevents the system from adopting long-range magnetic order at low
temperatures. Spin liquids continue to be of great interest due to their exotic
nature and the possibility that they may support fractionalised excitations,
such as Majorana fermions. Systems that allow for such phenomena are not only
fascinating from a fundamental perspective but may also be practically
significant in future technologies based on quantum computation. Here we show
that the underlying antiferromagnetic sublattice in TbInO$_3$ undergoes a
crystal field induced triangular-to-honeycomb dilution at low temperatures. The
absence of a conventional magnetic ordering transition at the lowest measurable
temperatures indicates that another critical mechanism must govern in the
ground state selection of TbInO$_3$. We propose that anisotropic exchange
interactions, mediated through strong spin-orbit coupling on the emergent
honeycomb lattice of TbInO$_3$, give rise to a highly frustrated spin liquid.
