Neglect to return from Baltimore (4)
I believe the answer is:
omit
'neglect' is the definition.
(synonyms)
'return from baltimore' is the wordplay.
'return' says the letters should be written in reverse.
'from' indicates the answer is hidden within the clue.
'timo' can be found hidden inside 'baltimore'.
'timo' reversed gives 'OMIT'.
'to' is the link.
(Other definitions for omit that I've seen before include "Disregard" , "Leave out or undone" , "Fail to use" , "Leave out, perhaps in error" , "Exclude; forget to include" .)