Meaning of mail cover | Babel Free
Definitions
An investigative technique in which the United States Postal Service, acting at the request of a law enforcement agency, records information from the outside of letters and parcels before they are delivered and sends that information to the requesting agency.
US
CEFR level
B2
Upper Intermediate
This word is part of the CEFR B2 vocabulary — upper intermediate level.
This word is part of the CEFR B2 vocabulary — upper intermediate level.