Entity
Entity or alien entity was a general term used to describe an individual or thing with different, unique, or interesting qualities. 

The term's meaning varied tentatively by user – where it usually meant the opposite of what the speaker identified themselves as – for example, a corporeal humanoid typically identified any non-corporeal or non-humanoid species as an entity. (, etc.) 

Q referred himself as an entity, and those that were not  as non-entities. () This was further acknowledged during the 's second encounter with Q, when Data referred to him as "the "Q" Entity". () Several years later Benjamin Sisko attended a Starfleet briefing on Q, and recalled two years later that Q was "a powerful and extremely unpredictable entity." ()

In 2366, Captain Jean-Luc Picard referred to Gomtuu, also known as "Tin Man," as a mysterious entity. ()

The non-corporeal Bajoran Prophets referred to the corporeal humanoids as physical entities. () 

Contrarily, in late 2369 Vedek Winn Adami took exception to Keiko O'Brien's use of the term "entities" to describe the aliens who constructed the Bajoran wormhole to her mostly Bajoran classroom of students. Upon hearing Mrs. O'Brien's lesson, Vedek Winn interrupted, and inquired, "by entities, do you not mean the Prophets?" Mrs. O'Brien's concurred, clarifying, "on Bajor the entities are worshipped as s." When Winn pressed the issue of O'Brien's scientific approach, versus the religious approach, the Vedek described it as "opening the children's minds to blasphemy." ()

See also 
 Chaos entity
 Double entity
 Life-entity transfer
 Microscopic entity
 Space entity

External link 
 
Lifeform classifications