LAY,
an Enterprize, or Attempt; To be sick of the Lay, to be tir'd in waiting for an Opportunity to effect their Purposes. Also an Hazard or Chance; as, He stands a quuer Lay; he stands an odd Chance, or is in great Danger.
Lay in the 1811 Vulgar Tongue
Also see examples in Canting Songs and Slang Rhymes collected by John S. Farmer (1896).