  The tilt-over mode in a precessing triaxial ellipsoid is studied
theoretically and numerically. Inviscid and viscous analytical models
previously developed for the spheroidal geometry by Poincar\'e [Bull. Astr. 27,
321 (1910)] and Busse [J. Fluid Mech., 33, 739 (1968)] are extended to this
more complex geometry, which corresponds to a tidally deformed spinning
astrophysical body. As confirmed by three-dimensional numerical simulations,
the proposed analytical model provides an accurate description of the
stationary flow in an arbitrary triaxial ellipsoid, until the appearance at
more vigorous forcing of time dependent flows driven by tidal and/or
precessional instabilities.
