Part of the Baltic you find frozen (3)
I believe the answer is:
icy
'frozen' is the definition.
(I know that frozen can be written as icy)
'part of the baltic you find' is the wordplay.
'part of' says the answer is hidden in the clue.
'ICY' is hidden in the letters of 'baltic you find'.
(Other definitions for icy that I've seen before include "Frosty and slippy" , "unsympathetic" , "Distant - freezing" , "Very cold, hostile" , "Posing danger on the road" .)