If you describe someone as ~, you mean that they are careful not to show their feelings or give away information.
The boy gave him a ~ look...
In the office, Dr. Lahey seemed less ~, more relaxed.
ADJ
~ly
‘I am happy, so far,’ he says ~ly...
They are ~ly optimistic that the market is on the road to recovery.
ADV: usu ADV with v, ADV adj, also ADV with cl