First of all, Aiago can't be used on boys because the name comes from a
Marian advocation (time ago,
Marian advocations' names were used also for boys, but not nowadays).
The place name Aiago is Basque, it has the toponymic suffix
-ago, "place with abundance of" or "place of", and a first part that it could be from
ahier, "incline, slope" (but this is not definitive, it could come from another word).
Lumia
http://onomastica.mailcatala.com