Being convenient, make an advance towards head (8)
I believe the answer is:
nearness
'being convenient make an advance towards head' is the definition.
I can't judge whether this definition defines the answer.
'make an advance towards head' is the wordplay.
'make an advance' becomes 'near' (I can't justify this - if you can you should believe this answer much more).
'towards' means one lot of letters go next to another (I've seen this in other clues).
'head' becomes 'ness' (ness is a headland).
'near'+'ness'='NEARNESS'
Can you help me to learn more?
(Other definitions for nearness that I've seen before include "Closeness" , "Propinquity" , "Quality of a mean person" , "Proximity" , "neighbour's property" .)