Skin somewhat ticklish, I declare (4)
I believe the answer is:
hide
'skin' is the definition.
('hide' can be a synonym of 'skin')
'somewhat ticklish i declare' is the wordplay.
'somewhat' says the answer is hidden in the clue.
'HIDE' is hidden within 'ticklish i declare'.
(Other definitions for hide that I've seen before include "Place to observe wildlife" , "A flower; an instrument" , "Secrete - animal skin" , "Keep out of sight" , "mask" .)