This can be used for writing about father in church (5)
I believe the answer is:
padre
This might be a double definition.
'this can be used for writing' is the first definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'father in church' is the second definition.
'padre' can be an answer for 'father' (synonyms). I'm not sure about the 'in church' bit.
'about' acts as a link.
Can you help me to learn more?
(Other definitions for padre that I've seen before include "Chaplain to armed forces" , "clerical worker" , "Army chaplain" , "Father" , "Minister" .)