1. English term that is used to refer to a “number set” of things. Thus quintuple and sextuple are examples representing a “five set” and “six set” respectively..
2. Used generically to describe a IP connection data set, thus, IP/Mask/Next Hop is known as the routing tuple, Source IP / Source Port / Destination IP / Destination Port is referred to as an IP Flow tuple, and
The IP routing tuple is network / subnet / next hop.
A host IP tuple is IP / mask / gateway (although some would corrupt the purity of IP with DNS entries in the data set.
I use this often in thinking over design and in documentation as it saves lot of typing.