Trounced and fired without a troublesome word (10)

'trounced' is the definition.
The answer and definition can be both to do with contact as well as being past participle verbs.
Perhaps there's an association between them I don't understand?

'fired without a troublesome word' is the wordplay.
'fired' becomes 'sacked' ('sack' can be a synonym of 'fire').
'without' is an insertion indicator ('without' can be similar in meaning to 'outside').
'a troublesome word' becomes 'hell' (I can't justify this - if you can you should believe this answer much more).
'sacked' going around 'hell' is 'SHELLACKED'.

'and' acts as a link.

Can you help me to learn more?