Concentrate on trimming end from confused composition (5)
I believe the answer is:
focus
'concentrate on trimming' is the definition.
'focus' can be an answer for 'concentrate' (I've seen this before). I'm not certain of the 'on trimming' bit.
'end from confused composition' is the wordplay.
'from' is a deletion indicator.
'composition' indicates anagramming the letters (letters arranged or composed in a different order).
'confused' with 'end' removed is 'cofus'.
'cofus' is an anagram of 'FOCUS'.
Can you help me to learn more?
(Other definitions for focus that I've seen before include "Concentration of attention or energy" , "Hub" , "Point or subject of interest or concentration" , "Concentrate, centre attention" , "Maximum clarity of an idea" .)