Troi and Riker held a conversation about the term and their relationship on the holodeck during a visit from Lwaxana Troi to the Enterprise-D. It was then stated imzadi could be used as well for platonic and for physical love. (TNG: "Haven")
While being telepathically violated, Troi flashed back to a conversation with Riker where they discussed being in a relationship while on the same ship. She kept flashing back to this memory, but with Riker's role being replaced by Jev and then Tarmin. (TNG: "Violations")
Riker again called Troi his imzadi when the two became intimate in their quarters on the USS Enterprise-E following the first part of their wedding ceremony on Earth. Moments later, during her telepathic mind rape, Troi was again called imzadi by both Shinzon and his Reman Viceroy. (Star Trek Nemesis)
At their house on Nepenthe in 2399, Riker half-scolded Troi by saying, "Easy there, imzadi," as the latter said she believed that Soji Asha's brusque assault of Jean-Luc Picard was not unwarranted. (PIC: "Nepenthe")
In the Peter David novels Imzadi and Triangle: Imzadi II, it was revealed that "imzadi" most basically translates as "first", although Troi clarifies that this term signifies the first person with whom one has shared not only physical intimacy, but spiritual as well. At the conclusion of Triangle, Worf refers to the recently-deceased Jadzia Dax as his imzadi, recognizing that the word defines their bond even if it does not originate from their cultures.