What Is the Definition of Marriage?

Marriage is defined differently, and by separate entities, based on cultural, religious, and personal factors. 

A commonly accepted and encompassing definition of marriage is a formal union and social and legal contract between two individuals that legally, economically, and emotionally unites their lives. The contractual marriage agreement usually implies that the couple has legal obligations to each other throughout their lives or until they decide to divorce. Being married also gives legitimacy to sexual relations within the marriage. Traditionally, marriage is viewed as having a key role in preserving morals and civilization. 

Additional Definitions

There are several definitions of marriage as described by these well-known resources:

Merriam-Webster

1. a: The state of being united as spouses in a consensual and contractual relationship recognized by law. b: The mutual relation of married persons [wedlock]. c: The institution whereby individuals are joined in marriage.
2. An act of marrying or the rite by which the married status is affected, especially: the wedding ceremony and attendant festivities or formalities.
3. An intimate or close union.

Dictionary.com

1. Any of the diverse forms of interpersonal union established in various parts of the world to form a familial bond that is recognized legally, religiously, or socially, granting the participating partners mutual conjugal rights and responsibilities and including, for example, opposite-sex marriage, same-sex marriage, plural marriage, and arranged marriage.
2. a: Also called opposite-sex marriage. The form of this institution under which a man and a woman have established their decision to live as husband and wife by legal commitments, religious ceremonies, etc. See also traditional marriage below. b: This institution expanded to include two partners of the same gender as in same-sex marriage.
3. The state, condition, or relationship of being married; wedlock.
4. The legal or religious ceremony that formalizes the decision of two people to live as a married couple, including the accompanying social festivities.
5. A relationship in which two people have pledged themselves to each other in the manner of a husband and wife without legal sanction.
6. Any close or intimate association or union.

Synonyms: matrimony, nuptials, institution, wedding, espousal, wedlock, formal union, social union, legal contract, merger, alliance

Same-Sex Marriage

In a landmark decision in the Obergefill v. Hodges case in June 2015, the United States Supreme Court held in a 5-4 decision that the fundamental right to marry is guaranteed to same-sex couples by both the Due Process Clause and the Equal Protection Clause of the 14th Amendment to the U.S. Constitution.

Different Types of Marriage

There are many alternative forms, common phrases, and definitions of marriage, including:

• Arranged marriage: Spouses are chosen by family members.
• Boston marriage: The union between two women.
• Celestial marriage: A Mormon term to describe a relationship destined to last beyond death.
• Civil marriage: A legal relationship that offers both parties rights and benefits at the state level.
• Common law marriage: A legally recognized union, although there is no marriage license. 
• Companionate marriage: A union based mainly on companionship.
• Cousin marriage: The betrothed couple are cousins.
• Covenant marriage: A union where both parties legally agree to stay together until death.
• Cyber marriage aka E-marriage: A marriage that takes place on the internet and is not legally binding.
• Endogamy: Marrying someone only from your local community.
• Eternal marriage: Same as covenant marriage.
• Exogamy: Marrying outside of your local community.
• Forced marriage: A marriage where one or both parties are forced into the union.
• Incestual marriage: A union where the spouses are related, such as a parent marrying their child.
• Interfaith marriage: The marriage between two people of different religions.
• Interracial marriage: The marriage between two people of different races.
• Intra-faith marriage: The union of two people of the same religion.
• Left-handed marriage: When the couple is of different social status, such as when a member of the royal family marries a non-royal.
• Marriage of Convenience: A union based on something other than love, such as financial gain.
• May-December marriage: This is when two people with a large age gap marry one another.
• Misyar marriage: A marriage contract between Sunni Muslims.
• Mixed marriage: A union between two people of different faiths or races.
• Morganatic marriage: Same as left-handed marriage.
• Monogamy: When partners only have sexual relations with one another.
• Open marriage: When a couple agrees they can have a sexual relationship with other people.
• Polygamy: Having more than one wife or husband at the same time.
• Polygyny: A man is married to several women at the same time.
• Polyandry: A woman is married to several men at the same time.
• Pragmatic: Same as arranged marriage.
• Proxy marriage: A union where one party cannot be present for the ceremony.
• Romantic marriage: A relationship where passion is of the utmost importance.
• Same-sex marriage: The marriage of two people of the same gender.
• Sealed marriage: A Mormon term for the marriage ceremony.
• Secret marriage: A marriage where only the spouses know it happened.
• Shotgun marriage: A union where the bride is pregnant.
• Urfi marriage: A Muslim ceremony where the marriage is not registered or legally binding.
• Zombie marriage: A relationship where the passion has died.