An independent entity.
"The team spent years engineering a lightweight indy that could withstand the extreme G-forces of the five hundred-mile race."
cars designed to meet the rules on the Indianapolis 500 car race.
In plain English: Indy is short for independent, describing someone who makes their own choices without relying on others.
"The indy at the front door was covered in mud from everyone running inside during the storm."
Independent, unaffiliated (especially not affiliated with a major organization or company).
"The indie band decided to self-release their album instead of signing with a record label."
In plain English: Indy means independent, showing that you can do things on your own without needing help from others.
"The indy movie was surprisingly popular with audiences everywhere."
Usage: Use "indy" as an adjective before a noun, such as in "an indy film," to describe something independent of major studios or organizations. Avoid using it for general independence unless specifically referring to projects outside large corporate structures.
Indianapolis.
"The team traveled to Indy for the big game on Saturday night."
Acronym of I'm not dead yet: a fruit-fly gene, mutant versions of which are said to have increased the organism's lifespan
"Researchers discovered that the indy gene in fruit flies may hold the key to extending their natural lifespan."
The word indy is a clipping that combines parts of Indianapolis and the suffix from independent to mean someone who acts alone or without affiliation. It entered common usage as a casual nickname for both the city itself and its residents.