Proper
Reasonable
noun, な adjective
おんとう
適当 （てきとう） Appropriate, Proper, Suitable, Irresponsible
穏当 （おんとう） Proper, Reasonable
It's Proper 穏当 to stay calm 穏 and correct 当 mistakes without losing composure.
The word ontology おんとう gives people a Proper scare.