  The expulsion dynamics of the last liquid monolayer of molecules confined
between two surfaces has been analyzed by solving the two-dimensional (2D)
Navier-Stokes equation for a compressible liquid. We find that the squeeze-out
is characterized by the parameter g0 ~ P0/(rho c^2), where P0 is the average
perpendicular (squeezing) pressure, rho the liquid (3D) density and c the
longitudinal sound velocity in the monolayer film. When g0 << 1 the result of
the earlier incompressible treatment is recovered. Numerical results for the
squeeze-out time, and for the time-dependence of the radius of the squeezed-out
region, indicate that compressibility effects may be non-negligible both in
time and in space. In space, they dominate at the edge of the squeeze-out
region. In time, they are strongest right at the onset of the squeeze-out
process, and just before its completion.
