Lither
Lither (lī"tẽr) , adjective
[Anglo-Saxon lȳeer bad, wicked.]
Bad; wicked; false; worthless; slothful. [Obsolete] — Chaucer
Not lither in business, fervent in spirit.
Professor Skeat thinks “ the lither sky” as found in Shakespeare's Henry VI. ((Part I. IV. VII., 21) means the stagnant or pestilential sky.