Liddell–Scott–Jones: μεσ-ευθύς

μεσ-ευθύς,ύ, gen.εος,

A. between the even ones: Pythag. name for the number 6 , ashalf-way between

2

and

10 , the first and last of the even (εὐθεῖς) numbers in the denary scale, Clem.Al. Strom. 6.139.2 .