Lexicon in this way accommodating a user that's confused (9)
I believe the answer is:
thesaurus
'lexicon' is the definition.
(thesaurus)
'in this way accommodating a user that's confused' is the wordplay.
'in this way' becomes 'thus' (synonyms).
'accommodating' indicates putting letters inside.
'that's confused' is an anagram indicator.
'a'+'user'='auser'
'auser' is an anagram of 'esaur'.
'thus' going around 'esaur' is 'THESAURUS'.
(Other definitions for thesaurus that I've seen before include "Book listing synonyms" , "Reference work" , "Wordy gathering" , "Dictionary" , "Book of words with synonyms, antonyms etc" .)