Carlos II of Spain is a case point for that problem; in delicate health, retarded, impotent, and terribly ugly, Carlos was the end result of generations of inbreeding among the Spanish Habsburgs.
She was a sickly little girl; her nose was always running and she coughed a lot.
2. Someone who is normally good looking but looks peculiarly bad either because they are ill or from lack of trying to look presentable
2. how do you feel? you're looking a little sickly today
3. you better put some makeup on or you'll look sickly