Father in the Army? (5)
I believe the answer is:
padre
'father in the army?' is the definition.
(I've seen this in another clue)
'in the army?' is the wordplay.
'in the' becomes 'pad' (I am not sure about this - if you are sure you should believe this answer much more).
'army?' becomes 'RE' (Royal Engineers army regiment).
'pad'+'re'='PADRE'
Can you help me to learn more?
(Other definitions for padre that I've seen before include "Army serviceman?" , "clerical worker" , "A military clergyman" , "Chaplain to armed forces" , "Services' chaplain" .)