Аннотация:We report an experimental and theoretical study of the low temperature 7 Li nuclear magnetic resonance (NMR) spectra of oriented powder samples of γ-Li 2 ZrCuO 4 (≡ Li 2 CuZrO 4) which comprises interpenetrating sublattices of frustrated quasi-one-dimensional s= 1/2 quantum Heisenberg magnetic Cu 2+ chains and frustrated quantum Ising electric sublattice of Li I ions. Incommensurate spin order occurring in this compound at T N⋍ 6 K gives rise to a drastic change of the 7 Li NMR spectrum. We show that the peculiar NMR line shapes are determined by the specific, sample dependent, distribution of the Li I ions in the glassy ordered electric sublattice. The analysis of the NMR data in the framework of a spin-spiral model gives evidence for a remarkable interaction between magnetic and electric degrees of freedom in γ-Li 2 ZrCuO 4, which suggests it as a promising model compound for fundamental studies of complex magnetoelectric phenomena and illustrates well their richness.