Regression (noun)

1. A return to a former or less advanced state.
2. A statistical analysis used to determine the relationship between variables.
3. A phenomenon in which an organism returns to an earlier stage of development.

Origin:

Late 19th century: from latin regressus "a going back", from the verb regredi, from re- "back" + gradi "to step".

Examples:

1. The country experienced economic regression after years of growth.
2. The regression analysis showed a strong correlation between education and income.
3. The regression in the amphibian's development allowed it to change its appearance and adapt to new environments.
4. The therapy helped the patient overcome the regression and regain their confidence.
5. The regression of the glacier was a result of rising temperatures and global warming.