Goes slowly for Speer at castle going all the way back (6)
I believe the answer is:
creeps
'goes slowly' is the definition.
(I've seen this in another clue)
'speer at castle going all the way back' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'speer' is 'reeps' which is within the answer.
A single letter 'c' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
Can you help me to learn more?
(Other definitions for creeps that I've seen before include "''Tomorrow, and tomorrow, and tomorrow, ... in this petty pace from day to day'' (Macbeth)" , "Toadies" , "treads softly" , "Moves slowly and stealthily" , "Moves silently and carefully" .)