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

• programmable
• programmatic
• programmer
• progress
• progressist
• progressive
• prohibit
• prohibition
• prohibitive
• project
• projectile
• projection
• projector
• prolapse
• prolate
• prole
• proles
• proletarian
• prolicide
• pro-life
• proliferate
• prolific
• prolix
• prologue
• prolong