  An unresolved, likely L dwarf companion to the DA white dwarf GD1400 is
reported. This would be only the second such system known, discovered 17 years
after the prototype L dwarf, GD165B, was determined to be a companion to a
white dwarf. Photometric observations and model predicted stellar parameters of
the well studied white dwarf primary indicate that GD1400B has $J-K\ga2.0$ and
$M_K=12.13$ mag. If correct, this would place GD1400B at spectral type L6, and
it would be the lowest luminosity unevolved companion known to a white dwarf,
and thus a definite brown dwarf. However, a low resolution Keck NIRSPEC
$2.1-2.4\mu$m spectrum may not be consistent with known L dwarfs. Uncertainties
in classification remain until the binary is resolved or a trigonometric
parallax is measured.
