  We investigate properties of the $N$(nucleon)-$\Omega$(Omega) interaction in
lattice QCD to seek for possible dibaryon states in the strangeness $-3$
channel. We calculate the $N\Omega$ potential through the equal-time
Nambu-Bethe-Salpeter wave function in 2+1 flavor lattice QCD with the
renormalization group improved Iwasaki gauge action and the nonperturbatively
$\mathcal{O}(a)$ improved Wilson quark action at the lattice spacing $a\simeq
0.12$ fm on a (1.9 fm)$^{3}\times$ 3.8 fm lattice. The $ud$ and $s$ quark
masses in our study correspond to $m_{\pi}= 875(1)$ MeV and $m_{K}= 916(1)$
MeV. At these parameter values, the central potential in the S-wave with the
spin 2 shows attractions at all distances.By solving the Schr\"{o}dinger
equation with this potential, we find one bound state whose binding energy is
$18.9(5.0)(^{+12.1}_{-1.8})$ MeV, where the first error is the statistical one,
while the second represents the systematic error.
