Empty forum probed about article (10)

I believe the answer is:

untenanted

I'm a little stuck... Click here to teach me more about this clue!

'empty forum' is the definition.
'untenanted' can be an answer for 'empty' (thesaurus). I am unsure of the 'forum' bit.

'probed about article' is the wordplay.
'probed' becomes 'untented' (I can't explain this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'article' becomes 'an' (English indefinite article).
'untented' enclosing 'an' is 'UNTENANTED'.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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