Reprimand male on tucking into a meal (8)
I believe the answer is:
admonish
'reprimand' is the definition.
(thesaurus)
'male on tucking into a meal' is the wordplay.
'male' becomes 'm' (common abbreviation).
'tucking into' is an insertion indicator.
'meal' becomes 'dish' (I've seen this in other clues**).
'm'+'on'='mon'
'a'+'dish'='adish'
'mon' inserted inside 'adish' is 'ADMONISH'.
(Other definitions for admonish that I've seen before include "Rebuke, tick off" , "Tell off" , "Gently reprove" , "censure" , "Caution - reprimand" .)