1.
Something that is ~ does not seem to have any sensible explanation.
For some ~ reason, it struck me as extremely funny...
= inexplicable
ADJ: usu ADJ n
unaccountably
And then, unaccountably, she giggled...
ADV
2.
If you describe a person or organization as ~, you are critical of them because they are not responsible to anyone for their actions, or do not feel they have to explain their actions to anyone.
Economic policy in Europe should not be run by an ~ committee of governors of central banks.
ADJ disapproval