Give, as a tip, a ball-point (5)
I believe the answer is:
endow
'give' is the definition.
(I've seen this before)
'a tip a ball-point' is the wordplay.
'a tip' becomes 'end'.
'a ball' becomes 'o'.
'point' becomes 'w' (W is an example).
'end'+'o'+'w'='ENDOW'
'as' is the link.
(Other definitions for endow that I've seen before include "Settle permanent income on" , "Woden (anag.)" , "Settle an income or property on" , "Set up with money" , "Attribute abilities to" .)