We report cluster glass behaviour mixed with short-range ferrimagnetic ordering in Co 0 . 2 Zn 0 . 8 Fe 2 O 4 spinel oxide. The AC susceptibility data show a maximum at T f 1 ~110K and a shoulder at T f 2 ~212K. The DC magnetization data also show a maximum at T m 1 ~110K and a shoulder at T m 2 ~260K. The frequency dependence of AC susceptibility and field dependence of DC magnetization data suggest a cluster spin-glass freezing at T f 1 ~110K. The appearance of shoulder in AC susceptibility data at T f 2 ~212K can be explained in terms of freezing of larger size clusters associated with anisotropy distribution. This is a pseudo-phase transition related to cluster size effect, rather than spin-glass-like freezing. The AC susceptibility, DC magnetization and room temperature Mossbauer spectroscopy measurements suggest that above 260K the magnetic phase is dominated by short-range interacting clusters in paramagnetic state, called cluster-paramagnetic phase and at 110K<T=<260K short-range ferrimagnetic phase coexist with cluster spin-glass phase, called mixed magnetic phase, in the present system.