Appear, say, with repairmen in service turning up (6)
I believe the answer is:
emerge
'appear' is the definition.
(emerge can mean to appear or arrive)
'say with repairmen in service turning up' is the wordplay.
'say' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'with' says to put letters next to each other.
'repairmen in service' becomes 'REME' (Royal Electrical and Mechanical Engineers).
'turning up' shows that the letters should be reversed in order.
'eg'+'reme'='egreme'
'egreme' back-to-front is 'EMERGE'.
(Other definitions for emerge that I've seen before include "Emanate" , "Come out or transpire" , "Come into view" , "Become gradually apparent" , "Gradually come out" .)