Corn one found in a labyrinth (5)
I believe the answer is:
maize
'corn' is the definition.
(I know that corn can be written as Maize)
'one found in a labyrinth' is the wordplay.
'one found' becomes 'i' (I've seen this in other clues).
'in' indicates putting letters inside.
'a labyrinth' becomes 'maze' ('maze' can be a synonym of 'labyrinth').
'i' going into 'maze' is 'MAIZE'.
(Other definitions for maize that I've seen before include "Corncob plant" , "source of food" , "Corn-cob cereal" , "Plant producing sweetcorn" , "plant with ears" .)