Here in Paris monarch is more aloof (5)
I believe the answer is:
icier
'more aloof' is the definition.
(I've seen this before)
'here in paris monarch' is the wordplay.
'here in paris' becomes 'ici' ('here' in French).
'monarch' becomes 'er' (abbreviation for Elizabeth Regina).
'ici'+'er'='ICIER'
'is' acts as a link.
(Other definitions for icier that I've seen before include "with more reserve" , "More reserved" , "Even more frozen" , "comparatively aloof" , "More cold - really freezing" .)