The notion of agriculture's Multifunctionality (MF) emerged in the 1980s. It then followed two trajectories since the 1990s: a conflicting period linked to its use in the international trade negotiations on the one hand, a spreading in terms of meaning, use and geographically on the other hand. Specific meanings appeared in connection with policy making, at national or international levels, or through the involvement of new disciplines. Yet, very few authors discuss the implication of the chosen meaning on their findings. To explore and take advantage of using this word and to deliver it from its controversial use in international trade negotiations, it is absolutely necessary to clearly understand the differences in the epistemological and ideological foundations behind different conceptions of MF. Highlighting the historical conditions in which the word emerged and was used, is an important but not sufficient pathway to interpret the diversity of meanings and uses and to make the word a meaningful, robust and operational concept for addressing Sustainable Development (SD) and designing adequate policies.