Sensitive sweetheart is ticklish, somewhat (8)
I believe the answer is:
artistic
'sensitive' is the definition.
'sweetheart is ticklish somewhat' is the wordplay.
'somewhat' indicates the answer is hidden within the clue.
'ARTISTIC' is hidden in the letters of 'sweetheart is ticklish'.
(Other definitions for artistic that I've seen before include "Showing creative skill" , "Aesthetically pleasing" , "crafty!" , "Naturally creative" , "displaying talent" .)