About lair at church showing rhythm? (7)
I believe the answer is:
cadence
'rhythm?' is the definition.
(cadence is a kind of rhythm)
'about lair at church' is the wordplay.
'about' becomes 'ca' (abbreviation for 'circa').
'lair' becomes 'den' (synonyms).
'at' is a charade indicator (letters next to each other).
'church' becomes 'CE' (abbreviation for Church of England).
'ca'+'den'+'ce'='CADENCE'
'showing' is the link.
(Other definitions for cadence that I've seen before include "Vocal modulation or inflection" , "Rhythm or beat" , "Modulation of the voice" , "Close of a musical phrase" , "Final musical sequence" .)