Strain, reportedly, to find love potion (7)
I believe the answer is:
philtre
'love potion' is the definition.
(I've seen this before)
'strain reportedly' is the wordplay.
'strain' becomes 'filter' (synonyms).
'reportedly' shows a homophone (sound like).
'filter' sounds like 'PHILTRE'.
'to find' acts as a link.
(Other definitions for philtre that I've seen before include "It makes you love" , "Exciting drink" , "Magic love potion" , "Love-potion" .)