ageless (adj.)

• age-old
• ancient
• antique
• auld
• ceaseless
• constant
• continual
• continuous
• dateless
• elderly
• endless
• eternal
• everlasting
• hoary
• immemorial
• incessant
• indestructible
• infinite
• interminable
• never-ending
• nonstop
• old
• old-time
• olden
• perdurable
• permanent
• perpetual
• sempiternal
• steady
• timeless
• unceasing
• unending
• uninterrupted
• unremitting
• venerable