primogeniture (n.)

• age
• ancientness
• antiquity
• atavism
• bequest
• birthright
• deanship
• eld
• eldership
• entail
• heirloom
• hereditament
• heritage
• heritance
• inheritance
• legacy
• oldness
• patrimony
• primitiveness
• reversion
• senility
• seniority
• succession
• venerableness