Lay, n. [OF. lei faith, law, F. loi law. See Legal.] 1. Faith; creed; religious profession.
Of the sect to which that he was born
He kept his lay, to which that he was sworn. Chaucer.
2. A law. “Many goodly lays.” Spenser.
3. An obligation; a vow.
They bound themselves by a sacred lay and oath. Holland.