English chap cuddling tense Republican? Heavens! (5)
I believe the answer is:
ether
'heavens' is the definition.
(thesaurus)
'english chap cuddling tense republican?' is the wordplay.
'english' becomes 'e' (abbreviation).
'chap' becomes 'he'.
'cuddling' means one lot of letters goes inside another.
'tense' becomes 't' (abbreviation used in many dictionaries).
'republican?' becomes 'r' (abbreviation).
'e'+'he'='ehe'
'ehe' going around 't' is 'ethe'.
'ethe'+'r'='ETHER'
(Other definitions for ether that I've seen before include "What's clear" , "Former anaesthetic" , "Volatile solvent" , "Anaesthetic; clear sky (poetic)" , "I'm volatile" .)