In Aberdeen, a dirty bottom? (5)
I believe the answer is:
nadir
'bottom?' is the definition.
(thesaurus)
'in aberdeen a dirty' is the wordplay.
'in' says the answer is hidden in the clue.
'NADIR' can be found hidden inside 'aberdeen a dirty'.
(Other definitions for nadir that I've seen before include "worst-case scenario?" , "least successful point" , "deep despair" , "lowest of the low" , "Dinar (anag.)" .)