The concept of functional load has been invoked for nearly a century in both research and pedagogy relating to pronunciation. However, it often suffers from a certain vagueness of definition. This article revisits the concept of functional load, outlining its origins and placing it within functionalist approaches to language and communication. The elaborated concept is then applied to the findings of lingua franca intelligibility studies, and it is argued that functional factors have explanatory potential. The application of functional load thus serves as a reinterpretation of the findings of lingua franca intelligibility studies by providing additional theoretical background. This reinterpretation suggests that although functional load is not a universal property of abstract language systems, certain features (such as consonants in general, and initial segments in particular) are widely relied upon in both lingua franca and non-lingua franca communication.