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

twin (either of two people who shared the same uterus, or of two similar or closely related objects) / one/a pair / corn cob (four or five small cobs glued together) / Gemini sign

(astrology) Gemini (a person born under the sign of Gemini)