Turkey, say, visited by English kings or colony dweller (7)
I believe the answer is:
meerkat
'colony dweller' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'turkey say visited by english kings' is the wordplay.
'turkey say' becomes 'meat' (turkey is a kind of meat).
'visited by' is an insertion indicator.
'english' becomes 'E' (abbreviation).
'kings' becomes 'RK' (R means rex - 'king' in Latin - and K means king).
'e'+'rk'='erk'
'meat' placed around 'erk' is 'MEERKAT'.
'or' acts as a link.
Can you help me to learn more?
(Other definitions for meerkat that I've seen before include "Small southern African mongoose" , "Mongoose-like mammal of southern Africa" , "South African mongoose" , "Mongoose-like mongoose" , "Rake met (anag) - type of mongoose" .)