tether

A rope, cable etc. that holds something in place whilst allowing some movement

A strong rope or line that connects a sailor's safety harness to the boat's jackstay

(by extension) the limit of one's abilities, resources etc.

The cardinal number three in an old counting system used in Teesdale and Swaledale. (Variant of tethera)

To restrict something with a tether.

To connect a cellular smartphone to another personal computer in order to give it access to a hotspot.