A pattern definition device for use in a charged-particle multi-beam processing or inspection apparatus, said device comprising an aperture field (af, xf) being adapted to be irradiated with a beam (lp) of electrically charged particles and allow passage of the beam through a plurality of apertures thus forming a corresponding number of beamlets, each of the beamlets traversing the aperture field (af, xf) along a respective beamlet path through the pattern definition device and extending downstream of the pattern definition device to a respective nominal path for each beamlet, said pattern definition device (102, 300, 500, 700, 900) including at least two deflection array devices (312, 322; 412, 422, 432, 442; 512, 522; 612, 622, 632, 642; 712, 722; 912, 922; 91, 92, 93, 94), which are positioned across said aperture field (af, xf) in a stacked arrangement such that each of the beamlets traverses at least two deflection array devices, each deflection array device having an area corresponding to the aperture field (af, xf), said area comprising - a plurality of blanking openings (313, 513, 523, 913, 923, 943) allowing passage of beamlets through the respective deflection array device, and - a plurality of deflecting devices, each of said deflecting devices being associated with a respective blanking opening (313, 513, 523, 913, 923, 943) and comprising at least one electrostatic electrode (310, 311, 410, 411, 420, 421, 430, 431, 440, 441, 510, 511, 520, 521, 710, 711, 720, 721, 770, 771, 910, 911, 920, 921, 940, 941), the deflecting devices being selectively activatable and configured to influence, when activated, the beamlets traversing said respective blanking openings so as to deflect said beamlets by an amount sufficient to divert said beamlets off their nominal paths (p0, p1), characterized in that for each deflection array device (312, 322; 412, 422, 432, 442; 512, 522; 612, 622, 632, 642; 712, 722; 912, 922; 91-94) the plurality of deflecting devices correspond to respective subsets (A, B) of the beamlets, such that each deflection array device is configured to act on only the beamlets belonging to the respective subset (A, B) of beamlets by selectively deflecting them while allowing the beamlets not belonging to the respective subset (B, A) to traverse the respective deflection array device without deflection, different deflection array devices of the pattern definition device (102, 300, 500, 700, 900) being configured to act on different subsets of beamlets, while the deflection array devices taken together are able to act on the entire number of beamlets. - a plurality of blanking openings (313, 513, 523, 913, 923, 943) allowing passage of beamlets through the respective deflection array device, and - a plurality of deflecting devices, each of said deflecting devices being associated with a respective blanking opening (313, 513, 523, 913, 923, 943) and comprising at least one electrostatic electrode (310, 311, 410, 411, 420, 421, 430, 431, 440, 441, 510, 511, 520, 521, 710, 711, 720, 721, 770, 771, 910, 911, 920, 921, 940, 941), the deflecting devices being selectively activatable and configured to influence, when activated, the beamlets traversing said respective blanking openings so as to deflect said beamlets by an amount sufficient to divert said beamlets off their nominal paths (p0, p1),