The mid part of a cilium between the ciliary base and ciliary tip that extends into the extracellular space.
Source:
GOC:krc,
GOC:cilia,
PMID:19866682
Comment
Note that 'ciliary shaft' is sparingly used in the literature to denote the projecting part of the cilium; many authors would refer to the axoneme instead. However, the definition of GO:0005930 'axoneme' is rather stringent, and the localization of many ciliary proteins would not fit that definition. Also, note that cilia and eukaryotic flagella are deemed to be equivalent.