  The evolution of lithium abundance over a star's lifetime is indicative of
transport processes operating in the stellar interior. We revisit the
relationship between lithium content and rotation rate previously reported for
cool dwarfs in the Pleiades cluster. We derive new LiI 670.8 nm equivalent
width measurements from high-resolution spectra obtained for low-mass Pleiades
members. We combine these new measurements with previously published ones, and
use the Kepler/K2 rotational periods recently derived for Pleiades cool dwarfs
to investigate the lithium-rotation connection in this 125 Myr-old cluster. The
new data confirm the correlation between lithium equivalent width and stellar
spin rate for a sample of 51 early K-type members of the cluster, where fast
rotating stars are systematically lithium-rich compared to slowly rotating
ones. The correlation is valid for all stars over the (J-Ks) color range
0.50-0.70 mag, corresponding to a mass range from about 0.75 to 0.90 solar
mass, and may extend down to lower masses. We argue that the dispersion in
lithium equivalent widths observed for cool dwarfs in the Pleiades cluster
reflects an intrinsic scatter in lithium abundances, and suggest that the
physical origin of the lithium dispersion pattern is to be found in the
pre-main sequence rotational history of solar-type stars.
