Undisciplined Irish men singing in a group - it's dreadful (8)
I believe the answer is:
horrific
'it's dreadful' is the definition.
(synonyms)
'undisciplined irish men singing in a group' is the wordplay.
I cannot really understand how this works, but
'men' could be 'rr' (R is short for rook - man can mean a chess piece) and 'rr' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for horrific that I've seen before include "Exciting intense fear and repugnance" , "Dreadful, horrendous" , "Terrifying" , "Inspiring intense fear" , "Dire" .)