Definition of "bi"

bi¹

/baɪ/

adjective
not comparable
1. (LGBT, slang) Bisexual.
2. (LGBT, slang, uncommon) Bigender.
noun
plural bis
1. (LGBT, slang) A bisexual person.
  Quotations
  For some reason, I'm feeling _very_ sensitive to bi-discrimination tonight. I'm really not trying to mock the points being made here, it's just that many of the same arguments can be turned around and used to describe the discrimination that bis face.
  1991 October 10, Ken Jones, “Re: Bisexual privilege? (Was Re: Tom Robinson Concert”, in soc.motss‎ (Usenet)
2. (bodybuilding, colloquial, uncommon) A biceps muscle.

/biː/