lea (lee, lay) noun

A grassland.

[From Old English leah (meadow). Ultimately from Indo-European root leuk-
(light) that has resulted in other words such as lunar, lunatic, light,
lightning, lucid, illuminate, illustrate, translucent, lux, and lynx.]

Hmm--all the ref.'s relating to light...did lea come about because a grassland is open? Nothing to make shadows, or to hide behind?