Social behavioral change communication interventions in Tanzania target populations engaging in high- risk sex behaviors and practices: anal intercourse, sex work, injecting drugs and male same sex relationships excluding women who have sex with women (WSW) or women who identify lesbians. In this paper, I describe terms used in reference to female same-sex sex or sexual relationships, important in health social behavior change communication targeting WSW in Tanzania. Data presented are part of cross-sectional descriptive and retrospective formative study among WSW conducted in Dar-es-Salaam region, Tanzania in 2021. WSW aged 18 and above, stayed in Dar-es-Salaam for six months or more; had had sexual contact with a woman in the past year participated in this study. Participants were recruited via snowball method. Community leaders/members and managers of NGOs/institution supporting WSW were purposively selected to take part in this study. Researchers used four methods to generated data needed for this study: focus group discussion, in-depth interviewing, observation and collecting WSW’s life stories. Content data analysis was conducted to create categories of terms around female same-sex sex or sexual relationships reported by study participants. Four categories of terms around female same-sex sex or sexual relationships emerged: terms referring to women who identify WSW or lesbians; terminologies referring to female same-sex sex; terms referring to female same-sex-related behaviors and practices; and terminologies referring to items/materials used during female same-sex sex. I conclude WSW in Dar-es-Salaam have coined terms that express their socially- created world. I recommend social behavior change communication programmers in the health education and promotion context to use these terms in developing comprehensive and WSW-friendly research protocols for sustainable behavior change among WSW and the public towards making female same-sex sex safe for reduced ....