Irregular Judge, old, accepting $1000 (6)
I believe the answer is:
jagged
'irregular' is the definition.
(thesaurus)
'judge old accepting $1000' is the wordplay.
'judge' becomes 'J' (abbreviation for judge).
'old' becomes 'aged' (similar in meaning).
'accepting' indicates putting letters inside (inserted letters are accepted).
'$a000' becomes 'g' (I've seen this in other clues).
'aged' placed around 'g' is 'agged'.
'j'+'agged'='JAGGED'
(Other definitions for jagged that I've seen before include "Of blade, uneven with sharp projections" , "Serrated" , "Having an irregularly notched or toothed edge" , "Having a sharply uneven surface or outline" , "Notched; rough-edged; uneven" .)