formidable
Concise Oxford English Dictionary © 2008 Oxford University Press:
formidable /ˈfɔːmɪdəb(ə)l, fɔːˈmɪd-/
▶adjective inspiring fear or respect through impressive size, strength, or capability.
– derivatives
formidableness noun,
formidably adverb.
formidableness noun,
formidably adverb.
– origin ME: from Fr., or from L. formidabilis, from formidare ‘to fear’.
'formidable' also found in these Oxford entries:

