An Etymological Dictionary of the German Language/Annotated/leer
leer, adjective, from the equivalent Middle High German lœ̂re, Old High German and Old Saxon lâri, ‘empty, void’; compare Anglo-Saxon lœre, gelœ̂re, Middle English ilêre, English dialectic leer, ‘empty, with an empty stomach, hungry.’ It can hardly be determined whether the r represents by rhotacism an earlier s. Perhaps Gothic lasiws, ‘powerless, weak,’ Anglo-Saxon lęswe, ‘weak’ (Middle High German erlęswen, ‘to grow weak’), as well as Old Icelandic lasenn, ‘demolished,’ are the nearest cognates of leer.
leer, if derived from Teutonic lêya, may be connected with Old Irish lia, 'hunger.'