A lemon is strangely sweet (8)
I believe the answer is:
semolina
'sweet' is the definition.
(I've seen this before)
'a lemon is strangely' is the wordplay.
'strangely' is an anagram indicator.
'a'+'lemon'+'is'='alemonis'
'alemonis' with letters rearranged gives 'SEMOLINA'.
(Other definitions for semolina that I've seen before include "Part of wheat used in puddings" , "Cereal used for puddings" , "dessert" , "Wheat powder" , "Wheat milk pudding" .)