rip-rap or riprap /ripˈrap/

1. Loose broken stones, used to form a foundation on soft ground or under water, or in the construction of revetments and embankments
2. A foundation formed of these

• ideation
• ideational
• ideationally
• ideations
• keepsakes
• keepsaky
• keep shtoom
• keep sight of
• keep someone at a distance
• keep someone going in something
• keep someone guessing
• keep someone in her place
• keep someone sweet
• keep something quiet
• keep something up one's sleeve
• keep step
• keep tabs on
• keep the ball rolling
• keep the field
• keep the flag flying
• keep the house
• keep the peace
• keep the pot a-boiling
• keep the pot boiling
• keep the ring