1. An effect observed when two or more conductors carrying alternating current are placed close to one another. The distribution of current across the cross section of any one conductor is changed under the influence of magnetic fields due to the other(s). The effective resistance of the conductor is modified by this effect and it is particularly significant in coils used at high (radio) frequencies.

2. In electron-beam lithography, unwanted exposure of the resist between two lines or patterns if these lines or patterns are exposed very close to each other.