circa1595William Shakespeare, Richard II, act 2, sc. 1:I do beseech your majesty, impute his wordsTo wayward sickliness and age in him.
1843, Charles Dickens, Martin Chuzzlewit, ch. 9:Gradually it gave place to a smile; a feeble, helpless, melancholy smile; bland, almost to sickliness.
1847, Anne Brontë, Agnes Grey, ch. 7:My devotions were disturbed with a feeling of languor and sickliness, and the tormenting fear of its becoming worse: and a depressing headache was generally my companion throughout the day.