Dictionary.net

• seks'tanz, n. an ancient Roman bronze coin, worth one-sixth of the as.--adjs. SEX'TANTAL; SEX'TIC, of the sixth degree. [L.,--sex, six.]

1908 - Chambers's Twentieth Century Dictionary of the English Language
By Thomas Davidson

• The sixth part of a pound.-Galen.

1846 - Medical lexicon: a dictionary of medical science
By Robley Dunglison