Write a pack of lies and they punish one (8)
I believe the answer is:
penalise
'punish one' is the definition.
'penalise' can be an answer for 'punish' ('punish'->'penalize' is in my internal thesaurus and 'ize'->'ise'). I am not certain of the 'one' bit.
'write a pack of lies and they' is the wordplay.
I cannot really understand how this works, but
'write' could be 'pen' (synonyms) and 'pen' is found within the answer.
'a' is found in the answer.
an anagram of 'lies' is 'lise' which is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for penalise that I've seen before include "Disadvantage unfairly" , "Inflict punishment on" , "Perhaps, fine" , "See plain (anag.)" .)