Conceited fellow given to publicity (4)
I believe the answer is:
toad
'conceited fellow' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'given to publicity' is the wordplay.
'given' means one lot of letters go next to another.
'publicity' becomes 'ad' (short for advert).
'to' put next to 'ad' is 'TOAD'.
Can you help me to learn more?
(Other definitions for toad that I've seen before include "Ancestral hall on River Bank" , "Contemptible person" , "Loathsome creature" , "Dangerous driver" , "Wind in Willows hall-owner" .)