Bathroom accessory excessively and thoroughly trimmed (5)
I believe the answer is:
towel
'bathroom accessory' is the definition.
(a towel might be used in a bathroom)
'excessively and thoroughly trimmed' is the wordplay.
'excessively' becomes 'to' (I can't explain this - if you can you should believe this answer much more).
'and' means one lot of letters go next to another.
'thoroughly' becomes 'well' (I've seen this before).
'trimmed' means to remove the last letter (the final letter is trimmed off).
'well' with its last letter removed is 'wel'.
'to'+'wel'='TOWEL'
(Other definitions for towel that I've seen before include "what sweater needs?" , "Piece of absorbent cloth or paper for drying" , "Bathroom item" , "Bathroom cloth" , "Dryer" .)