Very small part of coast in Yorkshire (4)
I believe the answer is:
tiny
'very small' is the definition.
(I've seen this before)
'part of coast in yorkshire' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'TINY' can be found hidden inside 'coast in yorkshire'.
(Other definitions for tiny that I've seen before include "Really small" , "pocket" , "Microscopic" , "Miniature" , "Slight" .)