unproper

The story

1. Proto-Indo-European*né
2. Proto-Indo-European*n̥-
3. Proto-Germanic*un-
4. Proto-West Germanic*un-
5. Old Englishun-
6. Middle Englishun-
7. Englishun-
8. Proto-Indo-European*per-der.?
9. Proto-Indo-European*pér
10. Proto-Indo-European*pró
11. Proto-Indo-European*pro-
12. Proto-Italic*pro-
13. Proto-Indo-European*preyH-
14. Proto-Indo-European*priHós
15. Proto-Italic*prijos
16. Proto-Italic*proprijos
17. Latinpropriu
18. Anglo-Normanpropre
19. Middle Englishpropre
20. Englishproper
21. English todayunproper

From un- + proper.

First known use, by meaning

• 14th–17th c. Improper, not according with fact or reason; wrong, irregular.
• from 16th c. Improper, not suited for its use or application; inappropriate.
• 17th c. Not belonging to a given person; someone else's.
• from 19th c. Improper, not according with good standards of behaviour; indecent, indecorous.