(idiomatic) Unlikely to happen or be important in the near future, or tending to escape detection or attention.

(idiomatic) Extemporaneous; without prior preparation; spontaneous; impromptu.

(idiomatic) As purchased or as commonly available, without modification or customization.

Not for publication. / Unofficial.

(of clothing, US) ready-made in a range of standard sizes

unofficial / secret

unofficially / secretly, in secret

(idiomatic) Free from work or direct supervision. In reference to slave labor, where workers are chained, or to the figurative chain of workers of an assembly line.

Beyond consideration.

Used other than figuratively or idiomatically: see off, rail. / (idiomatic) In an abnormal manner, especially in a manner that causes damage or malfunctioning / (idiomatic) Insane.