Office within the United States Office of the Secretary of Defense that investigates unidentified flying objects (UFOs) and other phenomena in the air, sea, and/or space and/or on land.

Physical retrieval of crashed UAP by humans, for reverse-engineering purposes.

Term for hidden civilisation, originating from and based on the Earth. Usually used to mean of contemporary human origin and a breakaway from mainstream society.

Advanced materials – for example made up of unusual isotopic ratios – the origin of which cannot be explained.

Someone who has seen or experienced the “Phenomenon”.

Term for advanced beings from the future who have travelled back in time to interact with us today.

Non-human intelligence from somewhere other than the Earth (i.e. ‘aliens’).

Short for the “intelligence community.” May encompass both military and civilian agencies and personnel.

A proposal that UAP sightings are the result of experiencing other “dimensions” that coexist separately alongside our own.

Short for the “Military Industrial Complex”. That is, the government military establishment and the private sector that works along with it.

A blanket term for any intelligent life of non-human origin, whether from the Earth or from off-world origins.

The anxiety that people feel as and when they realise that there are other non-human intelligences out there (and humankind is not top of the food chain).

A term used to denote a wider set of strange patterns and observations beyond UAPs that extends to the ‘paranormal’.

The idea of studying advanced craft or technology with a view to understanding how they work and recreating them.

Stands for ‘sensitive compartmented information facility’. It is an ultra-secure room where officials and government contractors take extraordinary precautions to review highly classified information.

Advanced civilisation emanating from the Earth, but much older than current human civilisations. Possibly survivors of a previous catastrophe (e.g. flood or meteor strike).

A more modern term for UFO that potentially avoids some of the stigma of the older term. (Aerial was changed to Anomalous as craft are potentially able to move through space and water, as well as the air).

An increasingly disregarded term for unexplained moving objects in the sky (with many practitioners preferring to use UAP instead).

A negative term used to describe more outlandish theories loosely connected to UAPs – such as the paranormal.