Nel Glossario del DIS la Sigint è definita:

Disciplina intelligence consistente nella ricerca ed elaborazione di notizie di interesse per la sicurezza originate  da segnali e/o emissioni elettromagnetiche provenienti dall’estero. Le principali branche della SIGINT sono la COMINT e la ELINT.

Entrambe “sottocategorie della Sigint” Communications Intelligence ed Electronic Intelligence sono definite:

Disciplin[e] intelligence consistent[i] nella ricerca ed elaborazione di notizie di interesse per la sicurezza nazionale provenienti da segnali emessi da sistemi elettromagnetici esteri di comunicazione [Comint] / provenienti da emissioni elettromagnetiche estere diverse dalle comunicazioni (per esempio, emissioni radar) [Elint].

In “Words of Intelligence” la Sigint viene definita come:

The collection of intelligence from nonpublic communications and other types of electromagnetic emissions such as radar and telemetry.

Mentre Comint ed Elint vengono definite, rispettivamente:

Technical information and intelligence derived from foreign communications by other than the intended recipients; it does not include the monitoring of foreign public media or the intercept of communications obtained during the course of counterintelligence investigations within the United States. Comint is produced by the collection and processing of foreign communications passed by electromagnetic means, and by the processing of foreign encrypted communications however transmitted. Collection comprises search, intercept, and direction finding. Processing comprises range estimation, transmitter/operator analysis, traffic analysis, cryptanalysts, decryption, study of plain text, the fusion of these processes, and the reporting of results. Comint includes the fields of traffic analysis, cryptanalysis, and direction finding, and it is a part of Signals Intelligence (Sigint).

Technical and intelligence information derived from foreign, noncommunications, electromagnetic radiations emanating from other than atomic detonation or radioactive sources; produced by the collection (observation and recording) and the processing for subsequent intelligence purposes of that information.