Ἀγ⍺θώ is a short form of a Greek masculine name commencing with the element ἀγαθο- (good).
Ἀγ⍺θώ [August Fick 1874 Die griechischen Personennamen nach ihrer Bildung erklärt, mit dem Namensystem verwandter Sprachen verglichen und systematisch geordnet, 1st edition, page 3].
Ἀγάθων [August Fick 1874 Die griechischen Personennamen nach ihrer Bildung erklärt, mit dem Namensystem verwandter Sprachen verglichen und systematisch geordnet, 1st edition, page 3].
Agatho [Joseph Stevenson 1838 Venerabilis Bedæ Historia Ecclesiastica Gentis Anglorum page 288].
Ἀγαθο- = gut [August Fick 1874 Die griechischen Personennamen nach ihrer Bildung erklärt, mit dem Namensystem verwandter Sprachen verglichen und systematisch geordnet, 1st edition, page 3].
A priest called Agatho attended the Council of Whitby: “Veneruntque illo reges ambo, pater scilicet et filius; episcopi, Colman cum clericis suis de Scottia, Agilberctus cum Agathone et Vilfrido presbyteris. Jacobus et Romanus in horum parte erant; Hild abbatissa cum suis in parte Scottorum, in qua erat etiam venerabilis episcopus Cedd, jamdudum ordinatus a Scottis, ut supra docuimus, qui et interpres in eo concilio vigilantissimus utriusque partis exstitit” [Joseph Stevenson 1838 Venerabilis Bedæ Historia Ecclesiastica Gentis Anglorum pages 221-222]: “The kings, both father and son, came thither, the bishops Colman, with his Scottish clerks, and Agilbert, with the priests Agatho and Wilfrid, and James and Romanus, were on their side; the Abbess Hilda and her followers were for the Scots, as was also the venerable Bishop Cedd, long before ordained by the Scots, as has been said above, and he was in that council a most careful interpreter for both parties” [John Giles 1845 The Ecclesiastical History of the English Nation, page 172].