European breaking tooth, perhaps, over herb (7)
I believe the answer is:
oregano
'herb' is the definition.
(I know that oregano is a type of herb)
'european breaking tooth perhaps over' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'breaking' means one lot of letters goes inside another.
'tooth perhaps' becomes 'organ' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'over' becomes 'o' (cricket abbreviation).
'e' inserted within 'organ' is 'oregan'.
'oregan'+'o'='OREGANO'
Can you help me to learn more?
(Other definitions for oregano that I've seen before include "aromatic plant" , "part of Mediterranean diet?" , "food flavouring" , "Dried marjoram" , "Marjoram-like herb" .)