Comhnasc

[Fitzys]

Dirty,tainted and contaminated . 8 letters. F .y . . . . .
Standard of perfection and excellence.5 letters. . . E . .
Moral principles. 6 letters. . T . . . .
Dispose or put an end to. 2 words, 3 letter and 2 letters

[Sam1960]

3. ethics

[Captain2]

2 of those answered on a previous thread of yours

http://www.theanswerbank.co.uk/Quizzes-and-Puzzles/Crosswords/Question1550091.html

[Captain2]

2 Ideal

[elliemay1]

Please use ? for missing letters, Fitzys

[Captain2]

Fitzys - please, please, please, ask requested before, use '?' instead of full stops to indicate letters (especially as you put a full stop at the end of each clue). It can be difficult to read.

[chiaroscuro]

Mop up

[Fitzys]

Sorry Captain2 and Elliemai I will use question marks in future for missing letters,

[elliemay1]

Thank you, fitzys

[Captain2]

:)))