FIRST is the Forum of Incident Response and Security Teams, which is an international forum of CERTs
ENISA: European Union Agency for Network and Information Security
ENISA is an acronym for the European Union Agency for Network and Information Security.
ENISA are involved in various aspects of cyber security across Europe, including advising countries and organisations on the NIS Directive.
DWI: Drinking Water Inspectorate
The DWI is the Drinking Water Inspectorate which is a part of DEFRA. The DWI is charged with oversight of the NIS Directive within the UK water sector.
DoS: Denial of Service
A DoS is Denial of Service which is a kind of cyber attack. See also DDoS.
DfT: Department for Transport
DfT is the Department for Transport which is part of the UK Government.
DFIR: Digital Forensics & Incident Response
DFIR is an acronym for Digital Forensics & Incident Response. DFIR is the set of processes which should be performed after a cyber attack.
DEFRA: Department for Environment, Food & Rural Affairs
DEFRA is the Department for Environment, Food & Rural Affairs which is part of UK Government.
DDoS: Distributed Denial of Service
DDoS is an acronym for Distributed Denial of Service, which is a type of cyber attack which aims to bring down a system or device.