1. in a sickly manner; in a way that suggests poor health or weakness
2. in an excessively sweet or sentimental way

Examples

• The patient smiled sicklily from his hospital bed.
• She looked sicklily pale after being indoors all winter.
• The child coughed sicklily throughout the night.
• The romance novel was sicklily sweet and unrealistic.
• He grinned sicklily, trying to hide his discomfort.
• The flowers drooped sicklily in the heat.