The word anatomy comes from the Greek ana-meaning up or through + tome meaning a cutting. Anatomy was once a cutting up because the structure of the body was originally learned through dissecting it. The word histology came from the Greek histo- meaning tissue + logos, treatise.
Definition: Reliability is the degree to which a measurement instrument gives the same results each time that it is used, assuming that the underlying thing being measured does not change.
In the context of computer networks, jitter is the variation in latency as measured in the variability over time of the packet latency across a network. A network with constant latency has no variation (or jitter). Packet jitter is expressed as an average of the deviation from the network mean latency. However, for this use, the term is imprecise.