tahkise osa, mille ulatuses aatomite paigutus on korrapärane ja korduv kolmemõõtmelises ruumis (vt kristallivõre; vrd tera), 1. a solid composed of atoms (ions or molecules) arranged in a pattern that is periodic in three dimensions; 2. that form, or particle, or piece of a substance in which atoms are distributed in one specific orderly geometrical array, called a "lattice" (see: lattice; compare: grain)