Chaps start to understand list of options (4)
I believe the answer is:
menu
'list of options' is the definition.
(I've seen this before)
'chaps start to understand' is the wordplay.
'chaps' becomes 'men' (chap means a man).
'start to' suggests taking the first letters.
The initial letter of 'understand' is 'u'.
'men'+'u'='MENU'
(Other definitions for menu that I've seen before include "List of dishes offered by restaurant" , "List of dishes available in restaurant" , "that can appear on computer screen" , "List of available food and drink" , "List of items to choose from as in restaurant" .)