Pushing up element of illicit pesticides that's toxic (6)
I believe the answer is:
septic
'toxic' is the definition.
Both the answer and definition are adjectives. Maybe there's an association between them I don't understand?
'pushing up element of illicit pesticides' is the wordplay.
'SEPTIC' is hidden backwards in amongst the letters.
However, I'm unsure how the hidden word is indicated.
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for septic that I've seen before include "Of wound, filled with pus" , "Poisoned" , "Putrid" , "Contaminated with disease-causing bacteria" , "Of wound, forming pus" .)