Spot on end of nose: kiss and turn! (5)
I believe the answer is:
exact
'spot on' is the definition.
(I've seen this before)
'end of nose kiss and turn' is the wordplay.
'end of' indicates one should take the final letters.
'kiss' becomes 'x'.
'and' is a charade indicator (letters next to each other).
'turn' becomes 'act' (theatre).
The final letter of 'nose' is 'e'.
'e'+'x'+'act'='EXACT'
(Other definitions for exact that I've seen before include "accurate in all details" , "Precise - demand" , "Meticulous" , "Absolutely right" , "Not approximate, precise" .)