1. having no ducts or tubes for carrying fluids
Usage: medical; anatomical
2. relating to endocrine glands that secrete hormones directly into the bloodstream
Usage: medical; biological

Examples

• The thyroid is a ductless gland that produces hormones.
• Ductless glands release their secretions directly into the blood.
• The pancreas has both ducted and ductless functions.
• Endocrine organs are also called ductless glands.
• The pituitary is an important ductless gland in the brain.
• Ductless air conditioning systems don’t require ventilation ducts.