plastron /plasˈtron/

1. A fencer's wadded breast-shield
2. The ventral section of the shell of a tortoise or turtle, or other animal
3. The front of a dress shirt
4. A separate ornamental front part of a woman's bodice
5. A steel breastplate worn under the hauberk (historical)

plasˈtral adjective

• sippets
• sipping
• sipple
• sippled
• sipples
• sippling
• sips
• sipunculid
• sipunculids
• sipunculoid
• sipunculoids
• si quis
• sir
• Sir.
• Sirah
• sircar
• sircars
• sirdar
• sirdars
• sire
• sired
• siren
• sirenian
• sirenians
• sirenic