Former learner round with eastern instrument (4)
I believe the answer is:
oboe
'instrument' is the definition.
(type of musical instrument)
'former learner round with eastern' is the wordplay.
'former learner round' becomes 'obo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'with' means one lot of letters go next to another.
'eastern' becomes 'e'.
'obo'+'e'='OBOE'
Can you help me to learn more?
(Other definitions for oboe that I've seen before include "Orchestral instrument" , "bit of wind" , "issuer of notes" , "blow it!" , "Walk with exaggerated movements" .)