What is a unicorn?
In the lifestyle, a unicorn is a single woman, often bisexual, who is open to connecting with a couple. The name reflects how rarely couples find someone in that role. She is an equal participant who sets her own terms and pace, not an accessory to a couple's fantasy.
The unicorn metaphor captures something honest about a supply-demand imbalance: couples looking for a single bisexual woman to join them are far more common than single women interested in that role. The term is widely used, though some people find it reductive because it treats the woman as a fantasy object rather than a full participant, and some women skip the label entirely.
Single women who do connect with couples have their own preferences, boundaries, and social needs. They are not accessories to a couple's experience. The encounters that go well are the ones where both partners treat the third person as an equal participant with her own comfort level and a veto she can use at any time, not as someone whose job is to satisfy the couple's agenda.
'Unicorn hunting' is the criticised version of this: a couple pursuing a single woman as an add-on, expecting her to fit their schedule, their rules and a scripted role, sometimes with an unspoken expectation that she will be equally attracted to both partners. Within the community the phrase is a warning label, and single women often use it to screen couples out.
If you are a couple hoping to connect with a single woman, build a genuine social presence in the community first, be explicit about what you are and are not looking for, let her set the pace, and accept a no without persuasion. Settings where single women choose whom to talk to tend to work better for everyone.
A unicorn describes a role, not a relationship. If three people want an ongoing, committed relationship with each other, that is a throuple, a different structure closer to polyamory. See the unicorn vs throuple answer and the hotwife lifestyle guide's table of identity terms for how the labels relate.