A toothed mobile part (1) for play take-up in a gear, particularly in horology, having certain (7) of its teeth fixed and entirely rigid, and other (8) of its teeth each intercalated between two rigid teeth (7) and elastically deformable, is characterised in that said elastically deformable teeth (8) consist of spring blades each comprising a gear flank (9), and in that for each spring blade (8) the distance (12) measured on the pitch circle (13) of the mobile part (1), between the gear flank (9) of the spring blade (8) and the corresponding flank (10) of the one among the two adjacent rigid teeth (7) facing the gear flank (9) is smaller than the distance (14), again measured on the pitch circle (13) of mobile part (1), between the gear flank (9) and the corresponding flank (10) of the other adjacent rigid tooth (7).