The Tocharian B word ṣkaste
Word ṣkaste
ʂ k ɐ s t e
IPA ʂkɐste
Meaning sixth

Comments
Douglas Q. Adams, “Etymological Dictionary of Tocharian B”, 1999, Brill

Other words that might be of interest
ṣe ‘one’, wi ‘two’, trey ‘three’, śtwer ‘four’, piś ‘five’, okt ‘eight’, okt-yaltse ‘eight thousand’, oktante ‘eighth’, oktamka ‘eighty’, piṅkte ‘fifth’, śtarte ‘fourth’, ñu ‘nine’, ñultse ‘nine thousand’, ñumka ‘ninety’, ñunte ‘ninth’, ṣukt ‘seven’, śak-ṣukt ‘seventeen’, ṣuktante ‘seventh’, ṣuktaṅka ‘seventy’, ṣkas ‘six’, śa(k)-ṣkäs ‘sixteen’, ṣkaska ‘sixty’, trite ‘third’, täryāka ‘thirty’, trai ‘three’