Take notice? No point (5)
I believe the answer is:
adopt
'take' is the definition.
(adopting is a kind of taking)
'notice? no point' is the wordplay.
'notice?' becomes 'ad'.
'no' becomes 'o' (resembles 0 - 'no' can mean 'zero').
'point' becomes 'pt'.
'ad'+'o'+'pt'='ADOPT'
(Other definitions for adopt that I've seen before include "make one's own" , "choose as candidate" , "Take up, follow" , "Foster" , "Espouse" .)