Skin of cucumber safe to eat, easy to swallow (8)
I believe the answer is:
credible
'easy to swallow' is the definition.
(I've seen this before)
'skin of cucumber safe to eat' is the wordplay.
'skin of' says to hollow out the word (remove centre letters).
'safe to eat' becomes 'edible' (I've seen this before).
'cucumber' with its middle taken out is 'cr'.
'cr'+'edible'='CREDIBLE'
(Other definitions for credible that I've seen before include "Convincing" , "Worth buying" , "Within the bounds of belief" , "Plausible" , "Likely to be believed" .)