Obscure English Tories upset with Commons at first (8)

Here is my best explanation:

'obscure' is the definition.
(thesaurus)

'english tories upset with commons at first' is the wordplay.
'english' becomes 'e' (abbreviation).
'upset with' indicates an anagram.
'at first' indicates taking the first letters.
The first letter of 'commons' is 'c'.
'tories' anagrammed with 'c' can make 'soteric'.
'e'+'soteric'='ESOTERIC'