Webster's Revised Unabridged Dictionary · 1913

Sext

Sext , noun

[Latin sexta, fem. of sextus sixtt, from sex six: compare French sexte.]

(a)
(R.C.Ch.) The office for the sixth canonical hour, being a part of the Breviary.
(b)
(R.C.Ch.) The sixth book of the decretals, added by Pope Boniface VIII.