Wasn't sure English model despised clothes (9)
I believe the answer is:
hesitated
'wasn't sure' is the definition.
The definition suggests a past participle verb which matches the answer.
'english model despised clothes' is the wordplay.
'english' becomes 'E' (abbreviation as in OED).
'model' becomes 'sit' (e.g. for a painting).
'despised' becomes 'hated' (synonyms).
'clothes' is an insertion indicator (inserted letters are clothed in others).
'e'+'sit'='esit'
'esit' going into 'hated' is 'HESITATED'.
Can you help me to learn more?
(Other definitions for hesitated that I've seen before include "was indecisive" , "Was reluctant" , "Paused, wavered" , "Was not keen" , "Thought twice" .)