1 : a written document that people sign to show that they want a person or organization to do or change something

• They collected 2,000 signatures on a petition demanding that women be allowed to join the club.
• Would you like to sign our petition?

2 a : a formal written request made to an official person or organization

• We presented a petition to the legislature to change the law.

2 b law : a formal written request to have a legal case decided by a court

• She filed a petition for divorce.
• They’ve denied your petition.

3 formal : a prayer or request to God or to a very powerful person or group

• We ask you to hear our petition.