Stronghold to be built with speed? (8)
I believe the answer is:
fastness
'stronghold' is the definition.
(I know that stronghold can be written as fastness)
'built with speed?' is the wordplay.
'built' becomes 'ness' (I can't explain this - if you can you should believe this answer much more).
'with' means one lot of letters go next to another.
'speed?' becomes 'fast' (I've seen this before).
'ness' put after 'fast' is 'FASTNESS'.
'to be' acts as a link.
Can you help me to learn more?
(Other definitions for fastness that I've seen before include "quality of not fading" , "Keep" , "Secure refuge" , "Stronghold or fortress" , "Strongly fortified defensive place" .)