Remember to gather about first (9)
I believe the answer is:
recollect
'remember' is the definition.
(I know that remember can be written as recollect)
'gather about first' is the wordplay.
I cannot quite see how this works, but
'gather' could be 'collect' (synonyms) and 'collect' is found within the answer.
'about' could be 're' ('re' means regarding or about) and 're' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'to' acts as a link.
Can you help me to learn more?
(Other definitions for recollect that I've seen before include "Bring back to mind." , "Look back on" , "Reminisce" , "Recall to mind" , "Remember" .)