Definition of "decompress"

decompress

/diːkəmˈpɹɛs/

verb
third-person singular simple present decompresses, present participle decompressing, simple past and past participle decompressed
1. (transitive) To relieve the pressure or compression on something.
2. (transitive) To bring someone (such as a diver) back to normal atmospheric pressure after being exposed to high pressure.
3. (transitive, computing) To restore (compressed data) to its original form.
4. (intransitive) To adjust to normal atmospheric pressure after being exposed to high pressure.
  Quotations
  The bad news is we got eight hours in this can blowin' down… And the worse news is, it's gonna take us three weeks to decompress later.
  1989, James Cameron, The Abyss (motion picture), spoken by Lindsey Brigman (Mary Elizabeth Mastrantonio)
  There was a typical reef construction here with large plating corals at deeper depths. Thankfully, again there were many new corals. We decompressed for several minutes before boarding. Then Mike really got sick. He skipped the next dive.
  2011, Max Gallimore, From Here to Caprock, page 354
5. (intransitive, informal) To relax.