The HIV-prevention behaviors of “abstinence” from sex, “being faithful” to one sexual partner, and “condom use” (ABC) are the focus of many international HIV interventions. Kenyan in-school youth ages 13-19 years (N = 1,375) were surveyed before the intended HIV-prevention intervention was implemented. As part of the survey, students wrote their definitions of the terms in a space provided. These definitions were qualitatively analyzed by determining recurrent themes, developing a codebook, and having two coders code the responses. The entire definition was assigned an overall fully comprehended, partly comprehended, did not comprehend, or no response code in comparison to the conventional definition of the term. Overall, 48% fully comprehended abstinence, 20% fully comprehended being faithful, and 7% fully comprehended consistent condom use. This suggests that these terms, and the meanings behind them, need additional clarification and discussion if they are to be used appropriately in HIV-prevention programs.