A small pool, especially of urine. Chiefly in "to do (also make) pooly": to urinate; to ejaculate.
Mid 19th century; earliest use found in James Halliwell (1820–1889), antiquary and literary scholar. From pool + -y.
Of the nature of or resembling a pool.
Mid 17th century; earliest use found in Henry Bell (fl. 1650). From pool + -y.