Outline you need help to lift weight (7)
I believe the answer is:
diagram
'outline' is the definition.
(outline can mean a diagram or map)
'help to lift weight' is the wordplay.
'help' becomes 'aid' (synonyms).
'to lift' says the letters should be written backwards (I've seen 'lifted' mean this (going up in down clue)).
'weight' becomes 'gram' (unit of weight).
'aid' written backwards gives 'dia'.
'dia'+'gram'='DIAGRAM'
'you need' is the link.
(Other definitions for diagram that I've seen before include "Explanatory illustration" , "Explanatory figure" , "scheme" , "Outline drawing showing parts or workings" , "I'm a drag (anag)" .)