cúlú, m. (gs. -laithe, pl. -luithe).1. vn. of cúlaigh. 2. Backing, reversal. ~ capaill, cairr, backing of horse, of car. 3. Retirement, withdrawal. ~ airm, withdrawal of army. 4. Mth: Regression. ~ lúibe, return of curve. 5. Waning. ~ gealaí, rabharta, waning of moon, ebbing of spring tide.