Finishes initial design in Spenser Centre (4)
I believe the answer is:
ends
'finishes' is the definition.
(I know this)
'initial design in spenser centre' is the wordplay.
'initial' indicates taking the first letters.
'in' indicates putting letters inside.
'centre' means to look at the middle letters.
The middle of 'spenser' is 'ens'.
The first letter of 'design' is 'd'.
'd' going within 'ens' is 'ENDS'.
(Other definitions for ends that I've seen before include "limits" , "designs" , "Stops in dens" , "Extremities" , "Brings to a close" .)