Stand in centre, man will follow line (7)
I believe the answer is:
tangent
'line' is the definition.
(I know that tangent is a type of line)
'stand in centre man will follow' is the wordplay.
'stand in centre' becomes 'tan' (I can't justify this - if you can you should give a lot more credence to this answer).
'man' becomes 'gent' (gent is a kind of man).
'will follow' says to put letters next to each other.
'tan'+'gent'='TANGENT'
Can you help me to learn more?
(Other definitions for tangent that I've seen before include "mathematician's line" , "Line that touches curve without crossing it" , "Trig ratio" , "Straight line touching a circle" , "A new line of thought" .)