We don't have synonyms for age-long yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are agelong, age long and geelong.
"They were waiting for me in the drawing-room, which is a very large room, stretching along the entire front of the house, with three long windows reaching down to the floor. -- Doyle"
"They were waiting for me in the drawing-room, which is a very large room, stretching along the entire front of the house, with three long windows reaching down to the floor. -- Doyle"