Caution adult Scotsman for breaking crockery (8)
I believe the answer is:
admonish
'caution' is the definition.
(synonyms)
'adult scotsman for breaking crockery' is the wordplay.
'adult' becomes 'a' (abbreviation).
'scotsman' becomes 'mon'.
'for breaking' indicates putting letters inside (inserted letters break their way in).
'crockery' becomes 'dish' (dish is a kind of crockery).
'mon' going within 'dish' is 'dmonish'.
'a'+'dmonish'='ADMONISH'
(Other definitions for admonish that I've seen before include "Reprove, warn" , "criticise" , "Gently reprove" , "Mildly reprove" , "Firmly reprimand" .)