SICK'LY, adjective 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.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI