Record difficult tie before disastrous semi (7)
I believe the answer is:
itemise
'record' is the definition.
('record'->'itemize' is in my internal thesaurus and 'ize'->'ise')
'difficult tie before disastrous semi' is the wordplay.
'difficult' indicates an anagram.
'before' says to put letters next to each other.
'disastrous' indicates an anagram.
'tie' anagrammed gives 'ite'.
'semi' is an anagram of 'mise'.
'ite'+'mise'='ITEMISE'
(Other definitions for itemise that I've seen before include "Formulate a list" , "Specify individually" , "Set down separately" , "Read off list of things one by one" , "List each thing separately" .)