iste

iste is the second person demonstrative, and Latin's three-way system is the point of it: hic is "this, here by me", iste is "that, there by you", ille is "that, over there away from both of us". English has lost the middle term, which is why translations reach for "that ... of yours".

It declines like ille with -st- in front: iste, ista, istud, genitive istius, dative isti, then ordinary first-and-second declension endings. Grammars often label it contemptuous, and in Cicero's prosecution speeches it certainly is, because "that client of yours" said across a courtroom carries a sneer. But the contempt is in the courtroom, not in the word. In late and medieval Latin the three-way system collapses and iste slides into meaning simply "this", which is where Spanish este and Italian questo come from.