Sesqui, Vocabulum in appositione inuentum. Cic.An muche and halfe as much: halfe as much more.Sesquiáltera pars. Ci. Somuch and halfe so much: a proportion in musick.Sesquiculeâre dolium Col.
Lewis and Short: Latin dictionary
sesquĭ (sesque), num. adv. [perh. contr. from semis-qui], one half more, more by a half. As a separate word it occurs only once: ut necesse sit partem pedis aut aequalem alteri parti aut altero tanto aut sesqui esse majorem (just after, sesquiplex), Cic. Or. 56, 188. But freq. joined in one word with designations of number or quantity, with the signif. of once and a half. Joined with numerals (octavus and tertius), like the Gr. e)pi/ (in e)po/gdoos, e)pi/tritos, etc.), it denotes an integer and such a fraction over as the numeral designates; v. sesquioctavus, etc.