An Etymological Dictionary of the German Language/Alter
Alter, n., ‘age, antiquity,’ from MidHG. alter, OHG. altar, n., ‘age, old age’ (opposed to youth); comp. the corresponding OSax. aldar, ‘life, time of life,’ AS. ealdor, ‘life,’ OIc. aldr, ‘age, hoary age,’ Goth. *aldra-, in framaldrs, ‘of advanced age, in years.’ An abstract term formed from the root al, ‘to grow up, bring forth,’ mentioned under alt, and the suffix -tro- frequent in Gr. and Lat. See further cognates under Welt.