IPA: /ˈlɪŋkʌp/
KK: /ˈlɪŋkˌʌp/
A connection or joining of two or more things, often used to describe a system or event where elements are linked together.
The linkup between the two satellites allowed for better communication in space.
Linkup → It is formed from "link" (from Old English *hlinc*, meaning to connect or tie) and "up" (meaning to a higher position or level). The word "linkup" refers to the act of connecting or joining things together, often in a more organized or elevated manner.
Think of 'linking' things together and 'up' suggesting a connection that is organized or elevated — that's what a linkup means.
No commonly confused words.