The present invention relates to an applicator for applying a composition to the eyelashes or the eyebrows, the applicator comprising: a stem extending along a longitudinal axis; and a brush fastened to the stem, the brush comprising: a core having a substantially rectilinear portion that slopes relative to the longitudinal axis of the stem; and bristles extending from the substantially rectilinear portion of the core, the bristles having free ends that define an envelope surface that presents at least one face having a generator line that is substantially parallel to the longitudinal axis of the stem.