Warning coin has landed a certain way (5,2)
I believe the answer is:
heads up
'warning' is the definition.
(I've seen this in another clue)
'coin has landed a certain way' is the wordplay.
I cannot really understand how this works, but
'coin' could be 'p' (abbreviation for pence) and 'p' is found within the answer.
'a' is within the answer.
'way' could be 's' (Compass direction - South) and 's' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for heads up that I've seen before include "Warning of impending event" , "Alert" , "Word to the wise" .)