Glucose (5)
(Other definitions for sugar that I've seen before include "Common sweetener" , "See 11" , "Sweeten" , "Term of affection" , "--- Ray Robinson, boxer" .)
'glucose' is the definition.
(synonyms)
This is all the clue.
(Other definitions for dextrose that I've seen before include "Form of sugar, in honey, say" , "Form of glucose" , "sweet stuff" , "sweetener" .)