Webster's Revised Unabridged Dictionary · 1913

Diatessaron

Diatessaron , noun

[Latin, from Greek {not transcribed} (sc. {not transcribed}); dia` through + {not transcribed}, gen. of {not transcribed} four (sc. {not transcribed}.).]

1.
(Anc. Music) The interval of a fourth.
2.
(Theology) A continuous narrative arranged from the first four books of the New Testament.
3.
An electuary compounded of four medicines.