One bottling can say reflects light (6)
I believe the answer is:
ignite
'light' is the definition.
(I've seen this in another clue)
'one bottling can say reflects' is the wordplay.
'one' becomes 'i' (Roman numeral).
'bottling' is an insertion indicator (bottling is a kind of containing).
'can' becomes 'tin' (synonyms).
'say' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'reflects' is a reversal indicator.
'tin' inserted within 'eg' is 'eting'.
'eting' written backwards gives 'gnite'.
'i'+'gnite'='IGNITE'
(Other definitions for ignite that I've seen before include "Kindle Fire" , "Cause to start burning" , "Burn" , "Spark off" , "Cause to catch fire" .)