Behaving like Jack, King and Queen in service (7)
I believe the answer is:
knavery
'behaving like jack' is the definition.
I can't tell whether this defines the answer.
'king and queen in service' is the wordplay.
'king' becomes 'K' (abbreviation for king in chess).
'and' means one lot of letters go next to another.
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'in' means one lot of letters goes inside another.
'service' becomes 'navy' (navy is a kind of service).
'er' put into 'navy' is 'navery'.
'k'+'navery'='KNAVERY'
Can you help me to learn more?
(Other definitions for knavery that I've seen before include "Chicanery" , "fraud" , "Villainy" , "Corrupt behaviour" , "Dishonest behaviour" .)