Spirit runs in by part of a steeple (6)
I believe the answer is:
belfry
'part of a steeple' is the definition.
(I've seen this before)
'spirit runs in by' is the wordplay.
'spirit' becomes 'elf' (I've seen this before).
'runs' becomes 'r' (cricket abbreviation).
'in' means one lot of letters goes inside another.
'elf'+'r'='elfr'
'elfr' inserted within 'by' is 'BELFRY'.
(Other definitions for belfry that I've seen before include "Part of a tower or steeple" , "Where to find peal" , "Bats in the campanile?" , "Place for ringers" , "Interior of a steeple (where bats hang out?)" .)