The most suitable one-word substitute of the following words:-
(a) A person who pretends to be someone else in order to deceive others.
(b) An assumed or false identity.
1
(a) Impostor (b) Incognito
2
(a) Heifer (b) Reality
3
(a) Henchman (b) Grisly
4
(a) Geek (b) Besmirch