Cross Contamination By Coot

[Matakari]

Good day, answers would be appreciated for the following, thanks!

www.crossword.org.uk/contamination.html

( Clashes appear in ten cells. A one-word description of the theme can be made using one set of letters, and a two-word description using the other set. Solvers should fill the grid using the former and write the latter under the grid. )

ACROSS:
4. Old funnymen's self-esteem wearing skimpy underwear? Not good (3,5):
?H?G???S
9. Favourite in garden? "Varied aster bed", admits King (9) :??D?R???T
11. Spirit level finally located behind a trailer, oddly (5) : A???L
13. Two-thirds of fish in pan sparkle, done very quickly (5-4) : ??I?D???E
DOWN:
1. Fight boy at wedding in process of getting wasted? (9) : S?????S??
16. Irritates one of the French retained doctors, perhaps (9) : G???????S
17. Fleet, initially failing to depart, tortuously trace signal (9) : T???????H
18. Quoted by awkward journalist (8) : ???D????
20. Cushion for footballer's quiet, stylish home (4,3) :??I????

[pomona]

27a anyone?

[Neveracrossword]

Pomona, 27 is Mower, what cuts.

[bobbinwales]

Not sure why / if Meze works myself pomona

[bobbinwales]

I thought def maybe 'egg on'

[bobbinwales]

So b urge r
Just a thought...

[pomona]

Thank you NACW for mower.
..and thank you bobinwales....your hint helped for that last one ...it is egg on for the defn ...rest of it ...B urge R

[pomona]

posts crossed ...thanks again!

[Neveracrossword]

Pomona, thanks - and it sounds as if you made great progress!

Matakari, did the answers for your second batch help you make great progress?!

[Matakari]

Made some progress here, but still not finished. I'll perhaps come back to it after tomorrow's Spectator!

[MontysMummy]

I have 9 of the 10 clashes and the other is lurking in 3d which I just cannot figure out:

Close match... dismissal... runs... edge... over (6) I have S*R*O*

However, even without the 10th clash I cannot see how to arrange the two sets of letters to give the two thematic descriptions which is usually quite straightforward at this stage. Without giving the game away (if possible) could anybody give me a gentle shove in the right direction?

Thanks!