Researchers typically note that there is much divergence about how rapport is defined in the investigative interviewing literature. We examined the scope of such variance, the commonalities of extant definitions, and how the current state of affairs impacts the scientific investigation of rapport. A formal search on the PsychInfo database obtained 228 relevant publications. Thirty-two publications explicitly defined rapport and 22 of those definitions were unique. All of the definitions implied that rapport centers on the quality of the interviewer-interviewee interaction. However, the definitions ascribed different attributes when describing how rapport relates to the quality of interpersonal interaction in an interview. A thematic analysis revealed six major attributes by which the definitions characterize interviewer-interviewee interactions that evoke rapport. The attributes were positivity, mutuality, communication, successful outcomes, trust, and respect. These attributes were disparately distributed across the definitions. Based on the considerable disparity in its definitions, we question the theoretical and practical value of the term rapport. The current situation creates ambiguity about the meaning of rapport and impedes its objective assessment. To avoid further ambiguity, we believe the field must collectively determine a finite set of attributes to denote the term rapport. Until this is achieved, stakeholders should stop indiscriminately using the word rapport to describe any collection of attributes of the interviewer-interviewee interaction.