Come into service? (6)
I believe the answer is:
enlist
This might be a double definition.
'come into' is the first definition.
(thesaurus)
'service?' is the second definition.
Although both the answer and definition are verbs in their base form, I cannot see how they can define each other.
Can you help me to learn more?
(Other definitions for enlist that I've seen before include "augment army" , "Engage" , "Join up - tinsel (anag)" , "Join the armed forces" , "Join the military" .)