Engagement
An engagement or betrothal was a formal agreement to get married. In some cultures, one partner will receive an engagement ring, a betrothal bracelet, or other form of engagement gift, from the proposing partner. (; )

Vulcans believed in arranged marriages, often established by their mutual parents' arrangement at the child's age as early as seven years. () When T'Pol explained to Koss that she was "not interested in marriage," he explained to her that "the decision isn't [theirs] alone," and that "[His] parents believe in the old traditions. For them, a betrothal cannot simply be dismissed." () A century later, when T'Pring and the nature of Spock's arrangement with her was revealed in 2267, he described the relationship as "less than a marriage but more than a betrothal. One touches the other in order to feel each other's thoughts." ()

Sometime prior to 2261, Christine Chapel and Roger Korby were engaged to be married, however, Korby disappeared not long thereafter. When the  was later contacted from the planet Exo III by Korby in 2266, Chapel, who was then serving aboard the ship, was present when they heard Korby speak over audio communications. When it was still in question whether the speaker was indeed Korby, Spock asked her if she was certain that she recognized his voice, she replied, "Have you ever been engaged, Mister Spock?" Before assuring, "Yes, it's Roger." () 

According to Miramanee, as "the daughter of the chief. Tribal law betroths me to our leader." ()

While speaking of the intertwined relations that had already developed between Starfleet officers and the Bajorans serving together on Deep Space 9 in early 2370, Commander Benjamin Sisko made mention of one such example, that being how Lieutenant Bilecki was engaged to a young man from Bajor. ()

Later that year, while discussing with Jadzia Dax the possibility of Melora Pazlar having a relationship with Julian Bashir, Pazlar gave an example of two friends of hers from Starfleet Academy that got engaged, "even though they knew they were being assigned to different starships" and despite the possibility of "not be[ing] together for a year or more and even then only for a few weeks." Upon learning this, Dax recognized that having a subspace relationship was "a tough one." ()

"A simple everyday business deal" between Ferengi was their form of engagement, which could include to "have a child", was "a standard five year marriage contract" which was signed by the male party, which was open to further extension. ()

In 2375, a falsified letter transmitted to Captain Kathryn Janeway by an alien lifeform was supposedly from her fiance Mark Johnson. This letter had him being engaged, rather than married, and stated that the engagement had broken off. () While entirely illusory, Janeway had previously received a letter from Mark, who she described to Chakotay as being from "the man I was engaged to," revealing that he had since gone on with his life and had gotten married to someone else. () Janeway later mentioned to Harry Kim that his feelings for Derran Tal were no different than hers were for "the man I was engaged to marry." ()

See also 
 Adversarial engagement strategy
 Dinner engagement
 Military engagement
 Social engagement

External link 
 
Social sciences
Ceremonies