... spice - or age on form (7)
I believe the answer is:
oregano
'spice' is the definition.
(I know that oregano is a type of spice)
'or age on form' is the wordplay.
'form' indicates anagramming the letters (another form of the letters).
'age'+'on'='ageon'
'ageon' with letters rearranged gives 'egano'.
'or'+'egano'='OREGANO'
(Other definitions for oregano that I've seen before include "part of Mediterranean diet?" , "Kitchen herb" , "Type of herb" , "aromatic plant" , "Pungent seasoning leaves" .)