olemus
Wiktionary, adj:
1. incapable of being reversed or turned about or back; incapable of being made to run backward
an irreversible engine
2. incapable of being reversed, recalled, repealed, or annulled
an irreversible sentence or decree
3. (thermodynamics) incapable of being reversed to the original state without consumption of free energy and increase of entropy

ülevaateid
http://www.idc-online.com/technical_references/pdfs/mechanical_engineering/Reversible_And_Irreversible_Process.pdf

https://en.wikipedia.org/wiki/Irreversible_process

vt ka
- pööramatu funktsioon
- pööramatu krüpteerimine