Agreement in the very essence (3)

I believe the answer is:

yes

'agreement' is the definition.
(saying yes to something)

'in the very essence' is the wordplay.
'in' indicates the answer is hidden within the clue.
'YES' can be found hidden inside 'very essence'.

(Other definitions for yes that I've seen before include "Absolutely" , "Aye" , "Certainly!" , "I agree" , "Indeed" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app