same, selfsame, identical, double, twofold, duplex, dual, twin (associated with sub-/objects that were born/created at the same time or a pair that derived from the same root) / neighboring, adjacent, adjoining (two adjacent, double parts) / similar, alike

Pacific Ocean (the world's largest body of water)

(botany) basil (Ocimum basilicum)

fava bean, broad bean (Vicia faba) / bean

Belgrade (the capital city of Serbia)

archipelago (group of islands)

(botany) pea (Pisum sativum)

ice cream (dessert)

reason / rationality / reason (cause)

Estonia (a country in Eastern Europe; capital and largest city: Tallinn)