All of the contents of a cilium, excluding the plasma membrane surrounding the cilium.
Note that we deem cilium and microtubule-based flagellum to be equivalent. Also, researchers consider the composition of both the plasm and the membrane of the cilium to be detectably different from that in the non-ciliary cytosol and plasma membrane (e.g. in terms of calcium ion concentration, membrane lipid composition, and more). For this reason, the term "ciliary plasm" is not linked to "cytoplasm".