Reckless old ruler wants some bacon (6)
I believe the answer is:
rasher
'some bacon' is the definition.
(I've seen this before)
'reckless old ruler' is the wordplay.
'reckless' becomes 'rash' (synonyms).
'old ruler' becomes 'er' (abbreviation for Elizabeth Regina. I am not sure about the 'old' bit.).
'rash'+'er'='RASHER'
'wants' is the link.
Can you help me to learn more?
(Other definitions for rasher that I've seen before include "Sliver of bacon" , "type of food" , "a little streaky?" , "More wildly adventurous" , "Comparatively ill-advised" .)