The Oxford Thesaurus An A-Z Dictionary of Synonyms - sicklyadj.

1) See sick, 2, above. 2) ailing, feeble, delicate, wan, weak, pallid, pale, drawn, peaked, peaky, peakish: Jennie looks sickly and must build up her resistance. 3) mushy, mawkish, maudlin, cloying, insipid, weak, watery: The sickly sentimentality of the episode about the boy and his lost puppy was unbearable.