Setter returns with stud to make an impression (6)
I believe the answer is:
emboss
'to make an impression' is the definition.
I can't judge whether this defines the answer.
'setter returns with stud' is the wordplay.
'setter' becomes 'me' (the setter of the clue).
'returns' is a reversal indicator.
'with' is a charade indicator (letters next to each other).
'stud' becomes 'boss' (synonyms).
'me' in reverse letter order is 'em'.
'em'+'boss'='EMBOSS'
Can you help me to learn more?
(Other definitions for emboss that I've seen before include "Bring about relief" , "Produce raised design" , "Make a surface design in low relief" , "Carve or mould a design to stand out in relief" , "Decorate with raised design (6)" .)