Tip case out, it's not contaminated (7)
I believe the answer is:
aseptic
'not contaminated' is the definition.
The answer and definition are not the same part of speech. However, adjectives and past participle verbs can occasionally define each other.
'tip case out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'tip'+'case'='tipcase'
'tipcase' with letters rearranged gives 'ASEPTIC'.
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for aseptic that I've seen before include "Free from bacteria, surgically clean" , "ideal conditions for hospital?" , "Sterile" , "Paciest (anag.)" , "Free from bacteria, surically clean" .)