Here are a few insults I invented to add to the list:
ragpicker: Humiliating insult for a githyanki of the lower castes. Commonly heard in the barracks as a means to test young githwarriors' self-control, for an undisciplined mind is a liability in battle, where level senses are needed.
blood-thinner: Some githyanki find themselves attracted to individuals outside of their people and for more racially-obsessive githyanki, these relations are an abomination. The resulting offspring are referred to as 'xho’xisth-stvokka' roughly translated as "lesser-kin".
ha’yadha-ph'naij: A person, either githyanki or another humanoid, suspected of having githzerai heritage somewhere in their family. This can also be employed to refer to an impossibility.
Example: Ras'thurkk and Jai-en'lin? That's ha’yadha-ph'naij if ever I heard of it!"
xho’xisth-stvokka: common insult for those with diluted githyanki blood. A person suspected of having a githzerai (horrors!) in the family tree is referred to as a 'ha’yadha-ph'naij', roughly translated as a 'greater abomination'
*ph'naij is also used to refer to bad luck, bad karma or as a term for someone who deserves to experience extreme suffering.