Rod is a chap I order to get a love potion (11)
I believe the answer is:
aphrodisiac
'a love potion' is the definition.
(I've seen this before)
'rod is a chap i order' is the wordplay.
'order' indicates anagramming the letters.
'rod'+'is'+'a'+'chap'+'i'='rodisachapi'
'rodisachapi' anagrammed gives 'APHRODISIAC'.
'to get' acts as a link.
(Other definitions for aphrodisiac that I've seen before include "Substance exciting sexual desire" , "Food or drink stimulating desire" , "Love stimulant" , "Exciting drug" , "Philtre" .)