Definition of sickly adjective from the Oxford Advanced American Dictionary
sickly
adjective
/ˈsɪkli/
sicklier, sickliest
1often sickHe was a sickly child.2not looking healthy and strongsynonymfrailShe looked pale and sickly.sickly plants3that makes you feel sick, especially because it is too sweet or full of false emotiona sickly sweet smellShe gave me a sickly smile.4 (of colors) unpleasant to look ata sickly green color