THE EUPHEMISM TREADMILL

5) Grzega: world view change (i.e. changes in the categorization of the world due to improved encyclopedic knowledge, a change in philosophies or cultural habits).
“first-degree word murder, first-degree lexicide” and “creation of lexical life” = non-institutional linguistic pre- and proscriptivism, institutional linguistic pre- and proscriptivism, taboo, aesthetic-formal reasons, disguising language, world view change
Consider Grzega's study on the concept of /young human female/ and the transition from "maiden" to "wench" and "lass" to "girl" (which he claims is not rooted in worldview change, but in semantic deterioration and the euphemism treadmill [for /prostitute/]):
Changing World View, Changing Categorization of the World 
We can speak of world view change when we refer to changes in the categorization of the world. It is not the referents that change, but the organisation of the content of the sign, the organization of the concept, the relevance of the referents in the world. This may, in turn, be due to a change of encyclopaedic knowledge, social and cultural habits etc. Example: That "girl" is more and more used to denote TEENAGE FEMALE HUMAN has to do with a changing view on what childhood and adolescence are, viz. that children and teenagers are not simply smaller versions of adults.
Lenker (1999: 11s.) reports that a basic world view change occurred during the 17th c., when children were gradually perceived not just as smaller versions of adults, but as weak and innocent. But this change does not seem to be in part responsible for any of the lexical innovations. The semantic restrictions all seem secondary. It can be observed, recurrently, that the words for the concept undergo semantic deterioration, i.e. they gradually denote “taboo” words; as a consequence, new terms have to be found for the neutral concept to avoid unintended associations [with euphemisms for /prostitute/!] (this is meant by “aesthetic-formal reasons”). If a word does not refer to a taboo concept, but equals a word referring to a taboo concept, its replacement can be said to go back to aesthetic-formal forces.
It can be observed, recurrently, that the words for the concept undergo semantic deterioration, i.e. they gradually denote “taboo” words; as a consequence, new terms have to be found for the neutral concept to avoid unintended associations [with euphemisms for /prostitute/!] (this is meant by “aesthetic-formal reasons”). If a word does not refer to a taboo concept, but equals a word referring to a taboo concept, its replacement can be said to go back to aesthetic-formal forces.
This phenomenon called euphemism treadmill can be seen in the following cases:

•  /female dog/ "bitch" -> "female dog" ("bitch"-> /prostitute/)
•  /young human female/ "lass," "wench" -> "girl," "maiden" ("lass," "wench" -> /prostitute/). Curiously: in German, "Dirne" underwent the same evolution as "wench:" 

"thiorna"/"Dirne" /young human female/ -> "Dirne" /prostitute/.

• /unmarried human female/ "spinster" -> "bachelorette" ("spinster" -> /old, unattractive/)
• /left/ across many languages: "sinistra" -> "izquierda" (es.), "esquerra" (cat.), "esquerda" (pt.) (from Basque "ezkerra" for /left/), "gauche" (fr., /awkward/), "stâng" (lt. "stancus/-a/-um" for "tired," "stagnant"); "winstre" (compare se. "vänster") -> "left" (/weak/); "laiós" -> "aristerós" (/the best/, same root as /aristocracy/).
• /bear/ in Russian ("medved," kenning meaning /honey eater/), /wolf/ in Swedish ("varg," kenning meaning /violent stranger/ [now that "varg" is no longer a euphemism, countryfolk say "grâben," i.e. /graylegs/]) and other fearsome predators which pose danger to humans: for the sake of respect
• "The LORD" used for /God/ in Abrahamic religions
• /death/: "the Grim Reaper," "der Sensemann," "la Catrina," "la Pálida Dama" (/death/ personified is masculine in Germanic cultures and feminine in Latin cultures)