indomitable
Concise Oxford English Dictionary © 2008 Oxford University Press:
indomitable /ɪnˈdɒmɪtəb(ə)l/
▶adjective impossible to subdue or defeat.
– derivatives
indomitability noun,
indomitableness noun,
indomitably adverb.
indomitability noun,
indomitableness noun,
indomitably adverb.
– origin C17 (in the sense ‘untameable’): from late L. indomitabilis, from in- ‘not’ + L. domitare ‘to tame’.
'indomitable' also found in these Oxford entries:

