Many studies in cognitive linguistics have analyzed the semantics of over, notably the semantics associated with over as a preposition. Most of them generally conclude that over is polysemic and that this polysemy is to be described thanks to a semantic radial network, showing the relationships between the different meanings of the word. What we would like to suggest, to the contrary, is that the meanings of over are highly dependent on the utterance context in which its occurrences are embedded, and consequently that the meaning of over itself is under-specified, rather than polysemic. Moreover, to provide a more accurate account of the apparently wide range of meanings of over in context, we ought to take into account the other uses of this unit: as an adverb and particle, and not only as a preposition. In this paper, we provide a corpus-based description of over which leads us to propose a monosemic definition.