1. Not healthy; somewhat affected with disease; or habitually indisposed; as a sickly person, or a sickly constitution; a sickly plant.
2. Producing disease extensively; marked with sickness; as a sickly time; a sickly autumn.
3. Tending to produce disease; as a sickly climate.
4. Faint; weak; languid. The moon grows sickly at the sight of day.
SICK'LY, verb transitive To make diseased.