sub rosa

/ˌsʌb.ˈɹəʊ.zə/

IPA: /S AH1 B R OW0 Z AH0/

noun
  1. 1

    (in workers' compensation cases) Covert surveillance video used to catch workers' compensation applicants and show that they are in fact not injured.

adjective
  1. 1

    Carried out secretly or confidentially.

adverb
  1. 1

    In secret or covertly; privately, confidentially.

    they held the meeting sub rosa

Source: https://en.wiktionary.org/wiki/sub%20rosa