A touching line from bronze chap (7)
I believe the answer is:
tangent
'a touching line' is the definition.
(I've seen this before)
'bronze chap' is the wordplay.
'bronze' becomes 'tan' (synonyms).
'chap' becomes 'gent' (I've seen this in other clues).
'tan'+'gent'='TANGENT'
'from' is the link.
(Other definitions for tangent that I've seen before include "Straight line that touches but does not intersect a circle" , "Straight line that touches but does not intersect a curve" , "At which one can go off" , "mostly irrelevant item" , "Line grazing another" .)