anamorphosis
Concise Oxford English Dictionary © 2008 Oxford University Press:
anamorphosis /ˌanəˈmɔːfəsɪs/
▶noun (pl. anamorphoses /-siːz/) a distorted image which appears normal when viewed from a particular point or with a suitable mirror or lens.
■ the process by which such images are produced.
– derivatives
anamorphic adjective.
anamorphic adjective.
– origin C18: from Gk anamorphōsis ‘transformation’.
'anamorphosis' also found in these Oxford entries:

