unterrifiableadj.
Etymology: Previous versions of the OED give the stress as: unˈterrifiable.
the mind > emotion > courage > fearlessness > dreadlessness > [adjective] > that cannot be terrified
1875 A. Helps xxiii. 352 There remain no unterrifiable witnesses but children.
This entry has not yet been fully updated (first published 1926; most recently modified version published online June 2019).