Zim And Gaz Romance (ZAGR) is the term for the couple Zim and Gaz from Invader Zim. It uses the same acronym that Zim And Gir Romance use.
Some fans theorize that one of the plots for the finale Invader Dib (that was later confirmed non-canon by Eric Trueheart; yet was possibly just a joke by Jhonen) would have officially paired them as a couple (through them teaming up to stop Dib from destroying the Irkens), voice actress Melissa Fahn support it, and Jhonen stated that had he wanted romance as a part of the show, he would have paired them up and thus she would perhaps be one of few humans spared from the wrath of the Irken Empire.
It is often compared to Nny and Devi's relationship in JTHM.