airtight

形容词 airtight:

1. having no weak points
   同义词：air-tight
2. not allowing air or gas to pass in or out
   同义词：air-tight, gas-tight

1. The goods are to be sent in airtight package.
   这批货物应密封包装运送。
2. An airtight excuse.
   无懈可击的借口