Look weary as you fall out, having started off (5)
I believe the answer is:
droop
'look weary as' is the definition.
I can't tell whether this defines the answer.
'fall out having started off' is the wordplay.
'fall out' becomes 'drop' (synonyms. I am not sure about the 'out' bit.).
'having' indicates putting letters inside.
'started' suggests taking the first letters.
The initial letter of 'off' is 'o'.
'drop' enclosing 'o' is 'DROOP'.
'you' acts as a link.
Can you help me to learn more?
(Other definitions for droop that I've seen before include "Hang downwards, lose strength or spirit" , "Become limp" , "Hang down loosely" , "Flag" , "Go limp" .)