From the cheapest source, they're unwanted (5)
I believe the answer is:
pests
'unwanted' is the definition.
The answer and definition are not the same part of speech.
'from the cheapest source they're' is the wordplay.
'from' indicates a hidden word.
'PESTS' is hidden in the letters of 'cheapest source theyre'.
Can you help me to learn more?
(Other definitions for pests that I've seen before include "Steps taken about nuisances" , "Persistently annoying persons" , "Take steps to troublesome animal." , "Steps (anag.)" .)