"an elderly man," is a longer form of presbus, the comparative degree of which is presbuteros, "a senior, elder," both of which, as also the verb presbeuo, "to be elder, to be an ambassador," are derived from proeisbaino, "to be far advanced." The noun is found in Luke 1:18 , "an old man;" Titus 2:2 , "aged men," and Philemon 1:9 , where the RV marg., "Paul an ambassador," is to be accepted, the original almost certainly being presbeutes (not presbutes), "an ambassador." So he describes himself in Ephesians 6:20 . As Lightfoot points out, he is hardly likely to have made his age a ground of appeal to Philemon, who, if he was the father of Archippus, cannot have been much younger than Paul himself. See OLD.
the feminine of No. 1, "an aged woman," is found in Titus 2:3 .
from geras, "old age," signifies "to grow old," John 21:18 ("when thou shalt be old") and Hebrews 8:13 (RV, "that which... waxeth aged," AV, "old"). See OLD.