Bi Definition formed in 1995 from the merging of two other bisexual support groups that met at the Counseling Center of Milwaukee, BiDesign (a women's group) and an unnamed men's group. Bi Definition exists to provide members with a sense of belonging not always found in the gay or straight communities. Members hold social gatherings and participate in local events such as PrideFest.

In response to declining attendance at business meetings and dwindling financial resources, Bi Definition voted to discontinue its print newsletter and regular meetings in 2004. The group said they would continue to meet socially and maintained a Web site, but all activity soon died out, and the web site was taken down.

Around 2018, a new group started, calling itself Bi+ Pride, with a placeholder website and primarily a presence on Facebook. See that organization's page here for more information.

The following purpose statement of Bi Definition is from the Group's web site.

Mission Statement
Bi Definition shall exist to facilitate the development of and maintain a cohesive bisexual community in metropolitan Milwaukee, WI. It will also promote bisexual visibility and education on bisexual issues.

Vision Statement
Bi Definition shall provide a social, support and activist organizational resource for bisexuals, people who do not like labels and their allies residing in and visiting metropolitan Milwaukee, WI. It shall work for equal rights and the liberation of all area bisexuals and others who refuse strict heterosexual and/or homosexual personal identification. Bi Definition will also collect and distribute information on bisexuality.

Governance Statement
In order to insure that all minority opinions are considered at business meetings, Bi Definition will use the consensus process of decision making for governing.

The UWM Archives LGBT Collection holds some of the Bi Definition's papers, including newsletters from 1996-2004.

'Bi All Means' newsletter (vol 2 no 1 - Spring 1997)	'Bi All Means' newsletter- first page only (vol 2 no 2 - Summer 1997)	'Bi All Means' newsletter- first page only (vol 2 no 4 - Winter 1997-1998)
'Bi All Means' newsletter- first page only (vol 3 no 1 - Spring 1998)	'Bi All Means' newsletter- first page only (Summer 1999)	'Bi All Means' newsletter- first page only (Summer 2001)
'Bi All Means' newsletter (Winter 2002-2003)