Melquiades Aragon was brother to my gr. grandfather Cornelio Aragon.Domacio F. Aragon could only be kin to both an Aragon and a Foulenfont.
Melquiades had several brothers and sisters.In order of birth, Jose Ignacio, Melquiades, Amado, Cornelio, Lilly, Carolina, Margarita, Justo, and Francisco.
The Aragon/Foulenfont lineage begins with Cornelio Aragon who married my gr. grandmother Maria Foulenfont.However, I have no record of a Domacio Foulenfont Aragon in my geneology.Domacio would have to have been offspring from Cornelio Aragon and Maria Foulenfont if he was an uncle (tio).
So to try and conclude whether this was a term of endearment or not the following lineage is provided.
Maria Foulenfont Aragon had only four children, in order of birth, Benjamin, Lillie, Carolina, and Samuel.
I have no geneology for Lilly Aragon who died in Las Vegas, NM at a young age from mental illness.However, it is unkown if she ever had children.
There is no geneology for Samuel Aragon because he died at age six.
I have extensive geneology for Benjamin (my grandfather) and some geneology for Carolina Aragon Garcia.
May I ask 'from whom' does the name Domacio F. Aragon come from, i.e. who were your grandfathers parents?This may help answer your question regarding Melquiades.