Quick answer
Aonghus is a boy name meaning "one strength".
Meaning and history
From Old Irish Óengus, possibly meaning "one strength" from óen "one" and guss "force, strength". Aonghus (sometimes surnamed Mac Og meaning "young son") was an Irish god of love and youth, one of the Tuatha Dé Danann. He was the son of the Dagda and Boann. The name was also borne by an 8th-century Pictish king, several Irish kings, and a few saints, including a 9th-century bishop of Tallaght.
Notes and context
Usage: irish, scottish gaelic, irish mythology