Aim head of arrow point (6)
I believe the answer is:
aspire
'aim' is the definition.
(synonyms)
'head of arrow point' is the wordplay.
'head of' suggests taking the first letters.
'point' becomes 'spire' (pointed tower of a church).
The first letter of 'arrow' is 'a'.
'a'+'spire'='ASPIRE'
(Other definitions for aspire that I've seen before include "Have a strong desire to achieve something" , "Aim at, work towards" , "Aim at high things" , "Hope, dream" , "Aim (for higher things)" .)