1. a covering or envelope, especially a membranous structure surrounding an organ or part
Usage: medical; biological
2. a whorl of bracts beneath a flower head or umbel
Usage: botanical

Examples

• The involucrum protects the developing tissue from infection.
• Surgeons carefully removed the involucrum during the bone procedure.
• The flower’s involucrum consists of several green bracts.
• In botany, the involucrum serves as protection for the inflorescence.
• The involucrum was clearly visible under microscopic examination.
• Each daisy has a distinctive involucrum at its base.