Crusader lawyer from Spain is presumably going to knock? (10)
I believe the answer is:
pilgrimage
'knock?' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pilgrimage that I've seen before include "special journey?" , "journey to shrine" , "Religiously inspired journey" , "Religiously-inspired journey" , "What Chaucer,s travellers were engaged upon" .)