Instrument for a University teacher oddly near nightshade (10)
I believe the answer is:
belladonna
'nightshade' is the definition.
The definition and answer can be both plants as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'instrument for a university teacher oddly near' is the wordplay.
'instrument for' becomes 'bella' (I can't justify this - if you can you should believe this answer much more).
'a university teacher' becomes 'don' (I've seen this in other clues).
'oddly' means one should take alternating letters (letters in the odd-numbered positions are used).
The alternate letters of 'near' are 'na'.
'bella'+'don'+'na'='BELLADONNA'
Can you help me to learn more?
(Other definitions for belladonna that I've seen before include "Deadly nightshade or atropine" , "plant" , "Drug made from deadly nightshade" , "brought a sparkle to the eye" , "Boy in Lebanon destroyed" .)