S: (n) climatic zone (any of the geographical zones loosely divided according to prevailing climate and latitude)
S: (n) time zone (any of the 24 regions of the globe (loosely divided by longitude) throughout which the same standard time is used)
S: (n) transit zone (a six million square mile area that includes the Caribbean and the Gulf of Mexico and the eastern Pacific Ocean; includes the principal routes used by drug smugglers)
S: (n) region, part (the extended spatial location of something) "the farming regions of France"; "religions in all parts of the world"; "regions of outer space"
S: (n) zona pellucida (thick membrane around the mammalian ovum; can be penetrated by one sperm in the fertilization process; usually remains around the fertilized egg until it is implanted in the wall of the uterus)