Track contained in habit (7)
I believe the answer is:
routine
'habit' is the definition.
(I've seen this before)
'track contained in' is the wordplay.
I cannot quite see how this works, but
'in' is found in the answer.
'track' could be 'route' (both can mean a path or line of travel) and 'route' is found within the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for routine that I've seen before include "Nothing unusual" , "Regular programme" , "Unvarying programme" , "Unvarying set of actions" , "Fixed sequence of actions" .)