fbi What is the Definition of fbi?Noun:a federal law enforcement agency that is the principal investigative arm of the Department of Justice Other meanings of fbi (synonyms, cognates). ENRU fbi фбр Frequently viewed: myself definitionbelieve meaningknowledge meaningspare meaningdefinition of ninelearn meaningstrict meaningpicture meaningpossible meaningzero meaningbehave meaningimmutable meaning A B C D E F G H I J K L M N O P Q R S T U V W X Y Z