Wreck a job by performing a lot of nonsense (11)
I believe the answer is:
jabberwocky
'nonsense' is the definition.
(I know that Jabberwocky is a type of nonsense)
'wreck a job by performing' is the wordplay.
'performing' indicates an anagram (the letters move around or 'perform').
'wreck'+'a'+'job'+'by'='wreckajobby'
'wreckajobby' anagrammed gives 'JABBERWOCKY'.
'a lot of' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for jabberwocky that I've seen before include "Lewis Carroll nonsense poem" , "Twas brillig poem" , "Lewis Carroll poem from "Through the Looking Glass"" , "Nonsense poem in Lewis Carroll's Through the Looking Glass" .)