Speech about granny oddly is generating concern (12)
I believe the answer is:
organisation
'concern' is the definition.
(I've seen this before)
'speech about granny oddly is' is the wordplay.
'speech' becomes 'oration' (oration is a kind of speech).
'about' is an insertion indicator.
'oddly' means one should take alternating letters (letters in the odd-numbered positions are used).
The alternating letters of 'granny' are 'gan'.
'gan'+'is'='ganis'
'oration' placed around 'ganis' is 'ORGANISATION'.
'generating' acts as a link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for organisation that I've seen before include "Systematic approach to tasks" , "Running" , "System" , "concern" .)