A term in Rugby: are rebellious teachers seen to be this? (7,3,4)

'a term in rugby' is the definition.
(term in rugby)

'are rebellious teachers seen to be this?' is the wordplay.
I cannot really understand how this works, but
'are' could be 'a' (the 'are' is a metric unit of area) and 'a' is found in the answer.
'be' could be 'head' (heading is a kind of being) and 'head' is located in the answer.
This may be the basis of clue (or it may be nonsense).