As it says in the dictionary of the RAE jayan comes from old jayant or gayant French, and means giant. I would add that " gayant " seems the 34 latin metathesis; gigant " ( read yigant = and metathesis " gayant " that translated its sound to the Spanish gives " 34 jayan;.
* Only one "like" per meaning and day, the more "likes" the meaning will appear higher in the list
