'To depart' is a formal verb.
'To reside' is an informal verb.
'To cease' is a formal verb.
'Meat-eater' is a formal noun.
'Home' is a formal noun.
'Insane' is a formal adjective.
'Senior' is an informal adjective.
'Perspiration' is a formal noun.
'Breathing' is an informal noun.
'To aid' is a formal verb.