The Jargon File (version 4.4.7, 29 Dec 2003):

gender mender
 n.

    [common] A cable connector shell with either two male or two female
    connectors on it, used to correct the mismatches that result when some 
    loser didn't understand the RS232C specification and the distinction
    between DTE and DCE. Used esp. for RS-232C parts in either the original
    D-25 or the IBM PC's bogus D-9 format. Also called gender bender, gender
    blender, sex changer, and even homosexual adapter; however, there appears
    to be some confusion as to whether a male homosexual adapter has pins on
    both sides (is doubly male) or sockets on both sides (connects two males).


The Free On-line Dictionary of Computing (30 December 2018):

gender mender
sex changer

    (Or "gender bender", "gender blender", "sex
   changer", and even "homosexual adaptor") A cable connector
   shell with either two male or two female connectors on it,
   used to correct the mismatches that result when some loser
   didn't understand the EIA-232C specification and the
   distinction between DTE and DCE.  Used especially for
   EIA-232C parts in either the original D-25 or the IBM PC's
   D-9 connector.

   There appears to be some confusion as to whether a "male
   homosexual adaptor" has pins on both sides (is doubly male) or
   sockets on both sides (connects two males).

   [Jargon File]

   (1995-04-16)