  We report the first measurement of a tune-out wavelength for ground-state
bosonic Dy and linearly polarized light. The tune-out wavelength measured is
near the narrow-line 741-nm transition in $^{162}$Dy, and is the wavelength at
which the total Stark shift of the ground state vanishes. We find that it
strongly depends on the relative angle between the optical field and
quantization axis due to Dy's large tensor polarizability. This anisotropy
provides a wide, 22-GHz tunability of the tune-out frequency for linearly
polarized light, in contrast to Rb and Cs whose near-infrared tune-out
wavelengths do not exhibit large anisotropy. The measurements of the total
light shift are performed by measuring the contrast of multipulse Kapitza-Dirac
diffraction. The calculated wavelengths are within a few GHz of the measured
values using known Dy electronic transition data. The lack of hyperfine
structure in bosonic Dy implies that the tune-out wavelengths for the other
bosonic Dy isotopes should be related to this $^{162}$Dy measurement by the
known isotope shifts.
