sickly

Short definition from Wiktionary

Adjective

1. 1
   Frequently ill or in poor health; weakly.
2. 2
   Not in good health; (somewhat) sick.
3. 3
   Characterized by poor or unhealthy growth. (of a plant)
4. 4
   Appearing ill, infirm or unhealthy; giving the appearance of illness.
5. 5
   Shedding a relatively small amount of light; (of light) not very bright.
6. 6
   Lacking intensity or vigour.
7. 7
   Associated with poor moral or mental well-being.
8. 8
   Tending to produce nausea.
9. 9
   Overly sweet.
10. 10
    Marked by the occurrence of illness or disease (of a period of time).
11. 11
    Tending to produce disease or poor health.

Verb

1. 1
   To make (something) sickly.
2. 2
   To become sickly.

Adverb

1. 1
   In a sick manner; in a way that reflects or causes sickness.