mystify

Concise Oxford English Dictionary © 2008 Oxford University Press:
mystify/ˈmɪstɪfʌɪ/

▶verb (mystifies, mystifying mystified) utterly bewilder.

■ make obscure or mysterious.

– derivatives
mystification noun,
mystifier noun,
mystifying adjective,
mystifyingly adverb.

– origin C19: from Fr. mystifier, formed irregularly from mystique ‘mystic’ or from mystère ‘mystery’.