i Register
In some senses, non-starter is marked as idiomatic. Watch for register when choosing this word.
noun
Someone or something who was listed to start in a race, but did not start in the race.
Something that is destined to fail from the outset; an impractical scheme.
Whatever is decided, it is clear that Crossrail 2 must be regarded as a non-starter for the foreseeable future.
An idea or argument that cannot be sensibly debated.