The process of declining from a higher to a lower level of effective power or vitality or essential quality.

synonym: devolution.

Dutch: achteruitgang, neergang, teruggang, verloop

The state of being degenerate in mental or moral qualities.

synonyms: decadence, decadency, degeneracy.

Roget 659: deterioration, debasement; wane, ebb; recession etc. 287; retrogradation etc. 283^†; decrease etc. 36.    degeneracy, degeneration, degenerateness; degradation; depravation, depravement; devolution; depravity etc. 945; demoralization, retrogression; masochism.    impairment, inquination^†, injury, damage, loss, detriment, delaceration^†, outrage, havoc, inroad, ravage, scath^†; perversion, prostitution, vitiation, discoloration, oxidation, pollution, defoedation^†, poisoning, venenation^†, leaven, contamination, canker, corruption, adulteration, alloy.    decline, declension, declination; decadence, decadency^†; falling off etc. v.; caducity^†, decrepitude.    decay, dilapidation, ravages of time, wear and tear; corrosion, erosion; moldiness, rottenness; moth and rust, dry rot, blight, marasmus^†, atrophy, collapse; disorganization; delabrement etc. (destruction). 162; aphid, Aphis, plant louse, puceron^†; vinefretter^†, vinegrub^†.    wreck, mere wreck, honeycomb, magni nominis umbra [Lat.]; jade, plug, rackabones [U.S.], skate [U.S.]; tackey^†, tacky [U.S.].    ... show more

Dutch: decadentie
Polish: zwyrodnienie, deformacja, wynaturzenie, degeneracja, zniekształcenie

Passing from a more complex to a simpler biological form.

synonym: retrogression.

Dutch: decadentie, kreeftegang, kreeftengang
Polish: degeneracja