This article explores why rapport seems challenging to define in the investigative interviewing literature. To demonstrate this issue is contemporary, I examined the most recent publications on rapport (August 2021 - January 2023; N = 19). Approximately 50% of the articles did not define rapport or posited multiple definitions, making a definitional preference impossible to detect. The 50% that specified a focal or single definition came with some form of suggestion that they were real definitions—the objective definitions of rapport. But all those definitions were different, highlighting the ambiguity of rapport in the literature. I discuss how a pragmatic approach via nominal definition can assist in flagging a single sense to use the word rapport, thereby eliminating ambiguity and limitations in assessing construct validity.