(verb) From , past participle of regredior ("to go back"), from re- ("back") + gradior ("to go").

• (noun) IPA: /ˈɹiːˌɡɹɛs/
• (verb) IPA: /ɹɪˈɡɹɛs/

regress

1. The act of passing back; passage back; return; retrogression.
   • 1886, Frederic Harrison, The Choice of Books:

     Its bearing on the progress or regress of man is not an inconsiderable question.

2. The power or liberty of passing back.
   • c. 1597 (date written), William Shakespeare, “The Merry Wiues of Windsor”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, (please specify the act number in uppercase Roman numerals, and the scene number in lowercase Roman numerals):

     Thou shalt have egresse and regresse.

3. (property law) The right of a person (such as a lessee) to return to a property.

   Coordinate terms: ingress, egress

• retrogress

regress (regresses, present participle regressing; simple past and past participle regressed)

1. (intransitive) To move backwards to an earlier stage; to devolve.
   1. (psychology) To re-develop behavior one had previously grown out of, particularly a behavior left behind in childhood.

      Your nightmares stopped when you were eight years old, but after the house burned down, you regressed.

2. (intransitive, astronomy) To move in the retrograde direction.(clarification of this definition is needed)
3. (intransitive, medicine) To reduce in severity or size (as of a tumor), without reaching total remission.
4. (transitive, statistics) To perform a regression on an explanatory variable.

   When we regress Y on X, we use the values of variable X to predict those of Y.

5. (transitive) To interrogate a person in a state of trance about forgotten elements of their past.
   • 2018, Michael Brein, Rosemary Ellen Guiley, The Road to Strange: UFOs, Aliens and High Strangeness:

     They regressed me, putting me under hypnosis. Then, through the hypnosis, they found out that our car was abducted right off the road and into a craft.

• backslide

• advance
• proceed
• progress

• French: régresser
• Portuguese: regredir, retroceder
• Russian: регресси́ровать
• Spanish: retrogradar, retroceder

• regression
• regressive