A number want sandwiches trimmed (8)
I believe the answer is:
neatened
'trimmed' is the definition.
The answer and definition can be both related to bodily activities as well as being past participle verbs.
Maybe there's an association between them I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for neatened that I've seen before include "Put in order" , "put straight" , "Straightened or tidied" , "Made tidy" , "Put to rights" .)