Mark on a Dalmatian (4)
I believe the answer is:
spot
'mark on a dalmatian' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for spot that I've seen before include "Mark - position - perceive" , "See; eruption" , "make out" , "precise location" , "Informally, catch sight of" .)