The Collaborative International Dictionary of English v.0.48:
linkup \linkup\ n. something that serves to join or link. Syn: link, tie, tie-in. [WordNet 1.5]WordNet (r) 3.0 (2006):
linkup n 1: a fastener that serves to join or connect; "the walls are held together with metal links placed in the wet mortar during construction" [syn: link, linkup, tie, tie- in]