  I point out that Gross-Neveu theory with SO(3) isospin in three spacetime
dimensions -- proposed recently, for instance, as an effective description of
the N\'eel transition in certain spin-orbital liquids -- also hosts quantum
criticality of a more exotic kind. The ordered phase breaks SO(3)
spontaneously, but the SO(3)-N\'eel order parameter vanishes. The fermionic
bilinear order parameter is, instead, a biadjoint with respect to SO(3); unlike
its N\'eel cousin, it constitutes an interaction-induced insulator.
Furthermore, I show that the N\'eel and biadjoint order parameters can be
combined to transform as an adjoint under SU(3) symmetry; the symmetry is
emergent at the critical point separating the symmetric semimetal and the
biadjoint insulator, but only if the flavour number is small enough, suggesting
order-parameter fluctuations and the interplay between different channels play
a crucial role in stabilizing the enlarged symmetry. In candidate SO(3)
spin-orbital liqiuds, thermodynamic critical exponents carry fingerprints of
"spinons". The existence of an independent universality class in addition to
the N\'eel transition opens the possibility of posing further constraints on
spinon properties from thermodynamic measurements near criticality alone.
