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

• spousage
• spousages
• spousal
• spousals
• spouse
• spoused
• spouseless
• spouses
• spousing
• spout
• spouted
• spouter
• spouters
• spout-hole
• spout-holes
• spoutier
• spoutiest
• spouting
• spoutings
• spoutless
• spouts
• spouty
• spoylefull
• spp.
• SPQR