umbo /umˈbō/

1. The central boss of a shield
2. A knob
3. The protuberant oldest part of a bivalve shell
4. A knob on a toadstool cap
5. A projection on the inner surface of the eardrum where the malleus is attached

umˈbonal /-bən-əl/ adjective

umˈbonate adjective (botany)

Having a central boss

• quill-nib
• quill-nibs
• quillon
• quillons
• quill-pen
• quill-pens
• quills
• quillwort
• quillworts
• quilt
• quilted
• quilter
• quilters
• quilting
• quilting bee
• quilting bees
• quilting-cotton
• quilting-frame
• quilting-frames
• quilting party
• persing
• Persism
• persist
• Persist
• persisted