a statement on a sworn document or attached to a sworn document about when, where, and before whom it was sworn
The judge held that the language of the jurat was clear and unambiguous.
(largely historical) someone who has taken an oath or who does something under oath
The jurat did take an oath. NB This is an antiquated use of English.
(largely historical) a public official, especially a magistrate (=a civil officer with the authority to administer the law)
William's father, Thomas Harvey, was a jurat of Folkestone where he served the office of mayor in 1600.