The Proto-Kartvelian word otxo-
Word otxo-
Meaning four

Comments
Heinz Fähnrich, Surab Sardshweladse: Etymologisches Woerterbuch der Kartwel-Sprachen, 1995 Brill

Other words that might be of interest
arwa- ‘eight’, c₁x(a)r- ‘nine’, eks1w- ‘six’, jor ‘two’, sam ‘three’, sam- ‘three’, šwid- ‘seven’, xut ‘five’