A matchmaker was somebody who conspired to bring people together romantically.
In 2372, when Jake suggested the couple spend three days in the Bajoran outback without him, saying he thought they'd have a better time without him, Benjamin told him to stop matchmaking. Jake clarified that he actually wanted to spend more time on his writing. (DS9: "The Muse")
In 2375, when Tom Paris encouraged Tuvok to pursue a relationship with Noss – given that USS Voyager might not rescue Paris and Tuvok and therefore the Vulcan might never see his wife again – Tuvok rejected Tom's attempt at "play(ing) matchmaker", as he was not in pon farr. (VOY: "Gravity")