watertight：不透水的，防水的；严密的，无懈可击的 

词根词缀：water水 + -tight紧的→密不透…的

• demilitarize
• demilune
• demi-monde
• demise
• demist
• demiurge
• demobilization
• demobilize
• democracy
• democrat
• democratic
• democratism
• democratize
• demographic
• demography
• demolish
• demon
• demonstrate
• demonstration
• demonstrationist
• demonstrative
• demonstrator
• demoralise
• demoralize
• demote