Rydberg-Rydberg transitions are induced by absorption from the lowest Rydberg state of NO A 2S+ (3ss) in Ar matrixes, which is excited by an ArF laser at 193.3 nm. The depopulation of the A(v = 0) level to higher Rydberg states is probed by depletion of its fluorescence. Absorption bands are obsd. in the 1.0-2.0 eV region which are attributed to transitions to the 3p, 3d, 4s and 4p members of the Rydberg series. At higher energies, a continuous absorption structure appears. It is attributed to transitions to the n>4 members of the Rydberg series which are compressed in a tiny energy range below the ionization potential. A quantum defect model is applied and accounts well for the observations. [on SciFinder (R)]