Loyal worker, not English shirker (6)
I believe the answer is:
truant
'shirker' is the definition.
(thesaurus)
'loyal worker not english' is the wordplay.
'loyal' becomes 'true' (I've seen this before).
'worker' becomes 'ant' (worker is a type of ant).
'not' indicates named letters should be taken away.
'english' becomes 'e' (abbreviation).
'true'+'ant'='trueant'
'trueant' with 'e' taken away is 'TRUANT'.
(Other definitions for truant that I've seen before include "Pupil who stays away from school with permission" , "Someone playing hookey from school" , "Schoolboy dodging school" , "One cutting school" , "'Bunk off'" .)