the property of being connected or the degree to which something has connections
"The new office building was designed for maximum connectivity, ensuring every floor could easily link to the main server room without bottlenecks."
The state of being connected
"After installing the new router, my laptop's connectivity finally improved enough to stream videos without buffering."
In plain English: Connectivity is how well different things are linked together so they can share information or work as a team.
"The hotel's poor connectivity made it difficult for guests to use their phones and laptops."
Usage: Use connectivity to describe the ability of devices or systems to link together and exchange data, such as in wireless internet access. Do not use it to refer simply to personal relationships or general social connections.
The word connectivity comes from combining the adjective connective with the suffix -ity to form a noun. It entered English by attaching these familiar parts together to describe the state of being connected.