Crossroads and Plug-in

Crossroads noun - A crisis situation or point in time when a critical decision must be made.

Plug-in and crossroads are semantically related In some cases you can use "Plug-in" instead a noun "Crossroads".

Plug-in noun - A printed circuit that can be inserted into expansion slots in a computer to increase the computer's capabilities.

Crossroads and plug-in are semantically related in link topic. Sometimes you can use "Crossroads" instead a noun phrase "Plug-in", if it concerns topics such as connection.